Paul, a servant of Christ Jesus, called to be an apostle, set apart for the gospel of God, 2 which he promised beforehand through his prophets in the holy Scriptures, 3 concerning his Son, who was descended from David according to the flesh 4 and was declared to be the Son of God in power according to the Spirit of holiness by his resurrection from the dead, Jesus Christ our Lord, 5 through whom we have received grace and apostleship to bring about the obedience of faith for the sake of his name among all the nations, 6 including you who are called to belong to Jesus Christ, 7 To all those in Rome who are loved by God and called to be saints: Grace to you and peace from God our Father and the Lord Jesus Christ.
The letter begins with a salutation of a form that was conventional in the Greco-Roman world. James Edwards notes that “Unlike the modern convention of beginning letters with an address to the recipient, salutations in the Greco-Roman world normally included three pieces of information: the name of the sender, the name of the recipient, and a brief greeting. Two letters recorded in the book of Acts (15:23 and 23:26) follow this pattern quite closely, as do 1 Thessalonians and James.”  Paul had, at the time of his writing, never visited the Roman church in person (Rom 1:13; 15:22-29). He thus expands his salutation so as to include a creedal summary of the gospel and his apostolic calling. Presumably Paul’s intent here was to establish credibility with the recipients of his letter, whom he had not yet met with in person.
As is customary for Paul’s letters, Paul begins with a self-introduction, including a statement of his credentials. Paul chose to make himself known by the name Παῦλος in all of his letters, even though, according to the book of Acts, he was known by the name Σαῦλος (Saul) at the time of his conversion and early on in his ministry career (Acts 9:1, 4, etc., 13:1-2, 7). Acts 13:9 indicates that Saul “was also called Paul.” As was common in the ancient world, Paul thus had a double name. James Dunn observes that “In Acts the transition from ‘Saul’ to ‘Paul’ as his regular self-designation more or less coincides with the beginning of his active (recorded) outreach to Gentiles beyond the eastern seaboard of the Mediterranean. Since ‘Saul’ was an unfamiliar name outside Jewish circles the transition to the more easily recognized name was a natural step.”  Why, though, is Paul consistently identified by the name Παῦλος, and never by Σαῦλος, after Acts 13 (except for Paul’s later recounts of his road to Damascus conversions)? Paul also consistently uses the name Παῦλος in every one of his letters. Paul’s consistent use of the name Παῦλος may reflect his commitment to his role as an apostle to the gentiles. James Dunn further argues that “the completeness of the change strongly suggests a transition in Paul’s self-perception, at least in terms of the social context within which he had his identity, perhaps a certain freeing of himself from the person he had been perceived to be as ‘Saul,’ or a willingness to engage in new relationships other than those enjoyed by ‘Saul.’” 
Paul writes that he is an “apostle, set apart for the gospel of God,” (Rom 1:1). The qualification for being an apostle was to have seen the resurrected Lord and to have been specially appointed to that office by Christ Jesus Himself. Paul writes elsewhere, “Am I not free? Am I not an apostle? Have I not seen Jesus our Lord?” (1 Cor 9:1). The necessitude of having witnessed the resurrected Lord is further attested in Acts, when the apostles appoint Matthias to replace Judas. Peter states that “one of these men must become with us a witness to his resurrection,” (Acts 1:22). Paul did have an encounter with the resurrected Lord on the road to Damascus and was commissioned to the office of apostle, albeit after Jesus had already ascended (Acts 9:1-19). For this reason, Paul writes, in describing the resurrection appearances, “Last of all, as to one untimely born, he appeared also to me,” (1 Cor 15:8). Paul himself also writes of his own appointment to the role of apostle by Jesus. For example, he writes, “For I would have you know, brothers, that the gospel that was preached by me is not man’s gospel. For I did not receive it from any man, nor was I taught it, but I received it through a revelation of Jesus Christ,” (Gal 1:11-12). He also asserts that “he who had set me apart before I was born, and who called me by his grace, was pleased to reveal his Son to me, in order that I might preach him among the Gentiles…” (Gal 1:15-16). Paul further stipulates that his apostleship is “not from men nor through man, but through Jesus Christ and God the Father, who raised him from the dead,” (Gal 1:1).
Paul, moreover, self-identifies as “a servant (δοῦλος) of Christ Jesus,” (Rom 1:1). The term δοῦλος literally means “slave.” Probably the intent behind this self-description is to assert his exclusive allegiance to the will and call of God. Craig Keener notes that “A slave of someone in high position had more status, authority and freedom than a free commoner; the emperor’s slaves were some of the highest-ranking people in the empire, as the Roman Christians would know. In the Old Testament, prophets from Moses on were generally called ‘servants’ or ‘slaves’ of God.”  Indeed, Moses (Josh 14:7), Joshua (Josh 24:29, David (Ps 89:3), the prophets, and Israel (Isa 41:8) are all identified as servants of the Lord. This meant that they were uniquely set apart by God. In like-manner, “God’s claim on Paul is total; Paul’s loyalty to God is final.” 
James Dunn notes that Paul’s self-identification as a slave of Jesus Christ “is the corollary of hailing Jesus as ‘Lord,’ but the degree to which the pious Jew’s exclusive devotion to the one God has now become or come to include the same sort of devotion to Jesus as risen from the dead and exalted to God’s right hand is highly significant as an indicator of how far developed the self-understanding of the Jesus movement already was (cf. Titus 1:1, ‘slave of God’).” 
The Gospel That Was Promised Beforehand Through His Prophets
Paul writes that the gospel for which he has been set apart was “promised beforehand through his prophets in the holy Scriptures…” (Rom 1:2). Besides the resurrection, this is the principle apologetic that is used throughout the New Testament, both by the apostles and by Jesus Himself. Luke, for example, tells us concerning Jesus’ interaction with the disciples on the road to Emmaus, “beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself,” (Lk 24:27). Jesus likewise says in John’s gospel, speaking to the Jewish religious leaders, “You search the Scriptures because you think that in them you have eternal life; and it is they that bear witness about me, yet you refuse to come to me that you may have life,” (Jn 5:39-40). The apostle Peter further recognizes that “Concerning this salvation, the prophets who prophesied about the grace that was to be yours searched and inquired carefully, inquiring what person or time the Spirit of Christ in them was indicating when he predicted the sufferings of Christ and the subsequent glories. It was revealed to them that they were serving not themselves but you, in the things that have now been announced to you through those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look,” (1 Pt 1:10-12) and “that no prophecy of Scripture comes from someone’s own interpretation. For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit” (2 Pt 1:20-21).
Jesus the Davidic Messiah
Paul notes that the Holy Scriptures spoke prophetically “concerning his son, who was descended from David according to the flesh.” Indeed, the Davidic descent of the Messiah is a common theme of the Hebrew Bible. For example, Isaiah spoke concerning the Messiah that “Of the increase of his government and of peace there will be no end, on the throne of David and over his kingdom…” (Isa 9:7) and that He would be “a shoot from the stump of Jesse” (Isa 11:1). The latter of those references calls the Messiah “a shoot from the stump of Jesse”, David’s father, rather than of David himself perhaps because at the time of the Messiah’s birth the house of David would have again been reduced to the obscurity of the days of David’s father Jesse. Another possibility is, as Alec Motyer suggests, “The reference to Jesse indicates that the shoot is not just another king in David’s line but rather another David. In the books of Kings, successive kings were assessed by comparison with ‘their father David’ (e.g. 2 Ki. 18:3) but no king is called ‘David’ or ‘son of Jesse’. Among the kings, David alone was ‘the son of Jesse’ (e.g. 1 Sa. 20:27–33; 1 Ki. 12:16), and the unexpected reference to Jesse here has tremendous force: when Jesse produces a shoot it must be David.”  Perhaps both of those explanations are in view.
In some passages, though written centuries after David’s death, the Messiah is even identified as David himself. For example, God spoke through the prophet Ezekiel concerning the nation of Israel, “And I will set up over them one shepherd, my servant David, and he shall feed them: he shall feed them and be their shepherd. And I, the LORD, will be their God, and my servant David shall be prince among them. I am the LORD; I have spoken,” (Ezek 34:23-24). Likewise, the prophet Jeremiah looked forward to a day when the people of Israel “shall serve the LORD their God and David their king, whom I will raise up for them,” (Jer 30:9). That these texts do not literally have David in mind, but rather a successor of David, is clear from what Jeremiah writes elsewhere: “Behold, the days are coming, declares the LORD, when I will raise up for David a righteous Branch, and he shall reign as king and deal wisely, and shall execute justice and righteousness in the land. In his days Judah will be saved, and Israel will dwell securely. And this is the name by which he will be called: ‘The LORD is our righteousness,’” (Jer 23:5-6; c.f. Jer 33:14-16). These texts also parallel the prophecies in the book of Isaiah concerning the righteous servant of God, who is also said to be a Davidic descendent (Isa 9:6; 11:1). The identification of the Messiah as David himself is similar to the identification of the Messiah as Israel (Isa 49:3) – who is nonetheless distinguished from Israel (Isa 43:5) – and the identification of the forerunner who would prepare the way for the Messiah (fulfilled in John the Baptist) as Elijah (Mal 4:5). It is also significant that the Messiah is foretold to be born in Bethlehem (Mic 5:2), given that Bethlehem was the birth place of David (Ruth 4:11,17).
Christ the Son of God
Returning to Romans, Paul goes on to say that Christ “was declared to be the Son of God in power according to the Spirit of holiness by his resurrection from the dead,” (Rom 1:4). The title “Son of God” is not disconnected from Paul’s identification of Christ as being “descended from David according to the flesh,” (Rom 1:3) since that title is used throughout the Hebrew Scriptures to refer to the Davidic heir (2 Sam 7:14; Ps 2:7; 89:27). Craig Keener notes that “Of course, Jesus is not God’s ‘Son’ only in the ordinary royal sense (cf. Rom 8:3, 29; Isa 9:6–7), but the good news that God has established a king, and hence his kingdom, sets Paul’s preaching of Jesus squarely in the context of the OT promises.” 
The significance of this may well be connected to David’s role in the Old Testament as a new Adam, as I shall discuss shortly. God promises David that “your house and your kingdom shall be made sure forever before me. Your throne shall be established forever,” (2 Sam 7:16). South African scholar John Ronning notes that “Since the dominion aspect of the neo-Adamic commission to the patriarchs was expressed as a promise of kings, and since David’s dynasty was to be perpetual, it seems apparent that he has now become heir of the promise of the new Adam given to the patriarchs. One can read 2 Sam 7:19 (and 1 Chr 17:17) as David’s recognition of this fact, as he exclaims, ‘and this is the law of mankind, O LORD God’ (with תּוֹרַת־הָאָדָם referring to the creation mandate of Gen 1:28).”  Ronning also observes a number of connections between 2 Samuel 7 / 1 Chronicles 17 (Nathan’s oracle to David) and Psalm 8 (which looks back towards the first Adam). For example, David says, “Who am I, O Lord GOD, and what is my house, that you have brought me thus far?” (2 Sam 7:18 / 1 Chr 17:16). This parallels Psalm 8:4, where David, speaking of Adam, says, “what is man that you are mindful of him, and the son of man that you care for him?” (Ps 8:4). Furthermore, David’s glorification can also be likened to that of the first Adam. David prays, “And what more can David say to you for honoring your servant? For you know your servant,” (1 Chr 17:18). This parallels Psalm 8:5 where David, speaking of Adam, says, “you have crowned him with glory and honor.” Finally, David speaks of the great name of the Lord both in Psalm 8:1,9 and in 2 Samuel 7:22-23 / 1 Chronicles 17:20-24. David also makes statements concerning himself in Psalm 21:3,5 which strikingly parallels that which is said of Adam in Psalm 8:5. Of himself, David says, “You set a crown of fine gold upon his head…Splendor and majesty you bestow on him,” (Ps 21:3,5). Compare this to Psalm 8:5, where he says of Adam, “You have crowned him with glory and honor.”
The nation of Israel is also identified as God’s Son (Hosea 11:1), and they are also considered to be the fulfilment of Adam. Genesis 4:16 indicates that Adam and Eve were expelled from the garden of Eden towards the East. This parallels how God later expelled the Hebrews from the promised land Eastward into Babylon. Genesis 11, which recounts the tower of Babel, is even set in what later became known as Babylon (Gen 11:1-9).  Adam, fittingly, is also identified as the son of God (Lk 3:38).
It is interesting, then, that both the Old and New Testaments represents Christ as the fulfilment of David, Israel and Adam, all of whom are identified by the Hebrew Bible as the son of God. We have already seen how Christ is said to be the greater David, both in the New and Old Testaments. But what about his identification with the nation of Israel? God speaks through the prophet Isaiah concerning His servant, “You are my servant, Israel, in whom I will be glorified,” (Isa 49:3). Thus, the servant is given the title Israel. Lest we be confused, however, as Michael Brown observes, the text subsequently goes on to differentiate the servant from the nation of Israel.  In verse 5, we read, “And now the Lord says, he who formed me from the womb to be his servant, to bring Jacob back to him; and that Israel might be gathered to him…” This is a continuation of a theme found also in Isaiah 42. Verses 1-7 deal with the righteous Messiah, calling Him the “servant”. Verses 18-25 contrast that righteous servant with the unrighteous servant, Israel. This theme is carried over into the New Testament. For example, in Matthew 4:1-4 we read of Jesus’ forty day fast in the wilderness, where he is tested by the devil. When the devil tempts Jesus to command the stones to become loaves of bread, Jesus replies by quoting Scripture: “Man shall not live by bread alone, but by every word that comes from the mouth of God,” (Mt 4:4). This is a direct quotation from Deuteronomy 8:3. The wider context of Deuteronomy 8:1-3 concerns Israel’s sojourn for forty years in the wilderness, during which time the people of Israel hungered and were tested. In fact, the Greek word translated “to be tempted” in Matthew 4:1 is πειράζω, which literally means “to be tested” — the very same (inflected) word used in Deuteronomy 8:2 in the Septuagint (ἐκπειράσῃ). Its Hebrew equivalent לְנַסֹּֽתְךָ֗ is used in the Hebrew text. Thus, we can see that just as Israel hungered and was tested for forty years in the wilderness, so likewise Jesus the Messiah hungered and was tested for forty days in the wilderness.
The New Testament also portrays Christ as the last Adam (Rom 5:12-21; c.f. 1 Cor 15:21-22, 45-49). This theme also is carried over from the Old Testament. In Daniel 7:13-14, we read of Daniel’s night vision concerning the figure whom he identifies by the title “one like a son of man.”
13 “I saw in the night visions, and behold, with the clouds of heaven there came one like a son of man, and he came to the Ancient of Days and was presented before him. 14 And to him was given dominion and glory and a kingdom, that all peoples, nations, and languages should serve him; his dominion is an everlasting dominion, which shall not pass away, and his kingdom one that shall not be destroyed.
There is, I would argue, a connection between the “son of man” title and Adam. In Daniel 7:14, the one like a son of man is given dominion over “peoples, nations and languages.” The kingdoms of men in this chapter are portrayed as beasts, which parallels the description in Psalm 8:7 as “beasts of the field” having been put under the “dominion” (v. 6) of Adam (c.f. Gen 1:28). In other words, the first son of man, Adam, has dominion over the animals; the second son of man, the Messiah, has dominion over the kingdoms of the earth, which are prophetically and allegorically portrayed as wild animals. Just as Adam received dominion on behalf of the entire human race (and required his offspring to fulfil it), the one like a son of man in Daniel 7:13-14 receives dominion on behalf of His offspring – that is, the saints of the Most High who will “possess the kingdom” (v. 22).
Still further support for the connection between Adam and the son of man comes from the Aramaic Targum Neofiti (of the Pentateuch), where Adam is referred to on several occasions as בר נשא, “the son of Man” (Tg. Neof. Gen 1:27; 2:18, 23; 9:6).  Targum Neofiti most probably dates to the first century A.D. If “the son of man” was a contemporary rendering of “Adam” in the Aramaic Targumim, then Jesus’ self-designation as “the son of man” also carried with it the implication that He is the true Adam.
Thus, the title “son of God”, when applied to Jesus, probably relates to Jesus’ fulfilment of those Old Testament types. The Old Testament also indicates that God has a divine son. Consider Proverbs 30:1-4:
The sayings of Agur son of Jakeh—an inspired utterance. This man’s utterance to Ithiel: “I am weary, God, but I can prevail. 2 Surely I am only a brute, not a man; I do not have human understanding. 3 I have not learned wisdom, nor have I attained to the knowledge of the Holy One. 4 Who has gone up to heaven and come down? Whose hands have gathered up the wind? Who has wrapped up the waters in a cloak? Who has established all the ends of the earth? What is his name, and what is the name of his son? Surely you know!
Here, in verse 4, we read of the son of God. What does the title son of God refer to here? The context can give us some clues. The first clue is that the phrase translated “Holy One” in verse 3 is in fact, in the original Hebrew, in the plural — literally, it is Holy Ones. Secondly, Agur is contemplating the incomprehensibility of God. He says in verse 3, “I have not learned wisdom, nor have I attained to the knowledge of the Holy One.” In other words, God is unfathomable. He then asks a series of rhetorical questions: “Who has gone up to heaven and come down? Whose hands have gathered up the wind? Who has wrapped up the waters in a cloak? Who has established all the ends of the earth?” The answer to each of those rhetorical questions is obviously God. He then concludes with a final rhetorical question: “What is his name, and what is the name of his Son? Surely you know!” To know someone’s name is a Jewish idiom for to understand their nature. Thus, the answer to the rhetorical question, based on the context, is “No, we don’t know the name because God’s nature is incomprehensible.” Thus, the nature of the Son is incomprehensible in just the same sense that the nature of God is incomprehensible. This suggests strongly that the Son being spoken of here is not a Davidic heir or the nation of Israel or Adam, but is in fact a divine person who is co-equal with God Himself.
Does Romans 1:4 Support Adoptionist Christology?
Though Romans 1:4 has often been used to support adoptionist Christology, I do not think it is Paul’s intent to assert that Christ merely became the Son of God at the time of the resurrection. More likely he is simply asserting that Jesus’ claim to be the Son of God was vindicated by His resurrection from the dead, or that his divine sonship was made publicly known through God raising Him from the dead. Craig Keener argues that “Paul here regards Jesus’ resurrection as the Spirit’s coronation of him as the Messiah and as humanity’s first taste of the future resurrection and kingdom.”  An old, but wise, hermeneutical principle is that unclear passages – that is, those that lend themselves to a plurality of interpretations – should be clarified by appeal to clearer texts, especially in work penned by the same author. Many texts within the Pauline corpus argue strongly against the adoptionist notion that the Son of God merely became the Son by the resurrection. For example, Paul writes elsewhere, “For you know the grace of our Lord Jesus Christ, that though he was rich, yet for your sake he became poor, so that you by his poverty might become rich,” (2 Cor 8:9). Furthermore, “God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin, he condemned sin in the flesh…” (Rom 8:3). Indeed, “when the fullness of time had come, God sent forth his Son, born of woman, born under the law” (Gal 4:4). Paul also argues that Christ “is the image of the invisible God, the firstborn of all creation. For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities – all things were created through him and for him. And he is before all things, and in him all things hold together. And he is the head of the body, the church. He is the beginning, the firstborn from the dead, that in everything he might be preeminent. For in him all the fullness of God was pleased to dwell,” (Col 1:15-19).
Romans 1:3-4 is often viewed as a pre-Pauline creed. Bart Ehrman summarizes the evidence for the pre-Pauline nature of this creedal statement. First, he notes that the text is “highly structured, without a word wasted, quite unlike how normal prose is typically written and unlike the other statements Paul makes in the context.”  Furthermore, even though the text is brief, it contains several words and concepts that are not found elsewhere in the Pauline corpus. For example, “Nowhere else in the seven undisputed Pauline letters does Paul use the phrase ‘seed of David’; in fact, nowhere else does he mention that Jesus was a descendant of David (which was a requisite, of course, for the earthly Messiah.”  Moreover, Ehrman notes, the phrase “Spirit of holiness” is not used elsewhere, and “Nowhere else does he ever talk about Jesus becoming the Son of God at the resurrection.”  Thus, Ehrman summarizes, “For a short two verses, those are a lot of terms and ideas that differ from Paul. This can best be explained if he is quoting an earlier tradition.”  Personally, I think the identification of these verses as an ancient creedal tradition is a reasonable conjecture, and this idea is indeed suggested by the language that is uncharacteristic of Paul (such as “Spirit of holiness”) and the tightly paralleled structure of these verses. Ehrman further suggests that these verses are “arguably the oldest fragment of a creed in all of Paul’s letters.”  In support of this, he points to the phrase “Spirit of holiness”, which some have recognized as a Greek Semitism, since πνεῦμα ἁγιωσύνης is an unusual Greek phrase and it may reflect the pattern of Aramaic or Hebrew phraseology. Bart Ehrman explains that “In Semitic languages, such as Hebrew and Aramaic, the language of Jesus and his followers, the way an adjective-noun construction is made is different from the way it is made in other languages such as English. In these Semitic languages, this kind of construction is made by linking two nouns with the word ‘of.’ For example, if you want to say ‘the right way’ in a Semitic language, you say ‘the way of righteousness.’ And instead of ‘Holy Spirit,’ you say ‘Spirit of holiness.’ This creed contains a clear Semitism, which makes it highly likely that it was originally formulated among Aramaic-speaking followers of Jesus in Palestine. And this means it could represent early tradition indeed, from the early years in Palestine after Jesus’s first followers came to believe that he had been raised from the dead.” 
Nonetheless, I do not regard the evidence as decisive. For one thing, as Simon Gathercole observes, “Even if the phrase ‘Spirit of holiness’ may have the ring of a ‘Semitism,’ this is not sufficient evidence to say that the creed goes back to an Aramaic original. As has been widely recognized in scholarship for a century or so, Semitisms are much more complicated than that.”  For a thorough discussion of some of the difficulties in inferring and attempting to reconstruct an underlying Hebrew or Aramaic original from a Greek text, I refer readers to James R. Davila’s detailed paper on the subject. 
Furthermore, though Ehrman is correct in his assertion that the idea of Jesus’ Davidic Messiahship is not stressed elsewhere in the undisputed Pauline corpus, Jesus is in fact identified as “the offspring of David” in 2 Timothy 2:8, which I take to be written by Paul in contradistinction to Ehrman (though I will not weigh the arguments for and against that conclusion here). Furthermore, Paul later in Romans identified Jesus as the “root of Jesse” (Rom 15:12), quoting from Isaiah 11:10. Thus, it is not accurate for Ehrman to assert that the concept of Jesus’ Davidic Messiahship is “a view not otherwise mentioned in the writings of Paul,”  even if we limit the “writings of Paul” to the undisputed corpus. In any case, while it is surely plausible that these verses represent pre-Pauline creedal tradition, the hypothesis is too speculative to confidently build an edifice upon it. Simon Gathercole concludes, “The key point is that one might well make the occasional speculation about this question, but to grant one’s speculations the force of probability such that one can then proceed to use them as foundations for other arguments is—not to put too fine a point on it—indefensibly bad method.” 
Nonetheless, on the quite plausible supposition that this text indeed reflects a pre-Pauline creedal tradition, then it would be in principle possible for one to argue that the text reveals the earliest Christology to be adoptionistic, even if Paul himself did not affirm this view. For example, according to Walter Schmithals, “The oldest and classical testimony to adoption Christology is found in Rom. 1:3–4” where “Jesus is presented only as one of many descendants of David, and such a lineage is a necessary presupposition for his adoption and exaltation as the messianic Son of God.”  Likewise, while Bart Ehrman acknowledges that Paul’s own view of Jesus included His pre-existence, he nonetheless argues that, for the original author of the creed that Paul is quoting from, “Jesus was the messiah from the house of David during his earthly life, but at the resurrection he was made something much more than that. The resurrection was Jesus’s exaltation into divinity.” 
It certainly must be recognized that, as the conservative Christian scholar Gordon Fee observes, “if this were the only text of its kind in the [Pauline] corpus, one could easily settle for an adoptionist Christology—Jesus becomes the ‘eternal’ Son at his resurrection and subsequent exaltation.”  Indeed, in the creed Jesus appears to undergo, as a consequence of His resurrection, a transition from an earthly status as Son of David to a divine status as the Son of God. Furthermore, the verb ὁρίζω (i.e. “to appoint” or “to declare”) may be rendered “to install.” On this translation, Jesus would not merely be declared to be the Son of God by means of His resurrection but rather would be, by divine fiat, installed as the Son of God following His resurrection.
However, one has to be careful in how much one infers from creedal formulas since, as Michael Bird, notes, “The creedal formulas and traditional materials that we find scattered across the New Testament are intended as abbreviated confessions of faiths, succinct to a point but ultimately insufficient, functioning as symbols and signs of a wider body of beliefs. They are not comprehensive in their affirmations, and they make no denials. They are, in other words, the ancient equivalent of a doctrinal bumper sticker or the condensing of a complex theological topic into a single message. So we should not assume that these densely packed sentences were the totality of what people believed about Jesus, or that early Christians were disinterested or even opposed to anything else that might be said about Jesus.” 
One problem for the adoptionist interpretation of Romans 1:4 is that the prepositional phrase ἐν δυνάμει (“in power”) is inconsistent with the adoptionist view, since it “portrays Jesus not as becoming the Son of God for the first time, but becoming the Son of God in a new way, in power.”  James Edwards likewise interprets those verses to indicate that “At the resurrection Jesus was constituted Son of God in power, whereas before the resurrection he had been Son of God in suffering. Thus, verses 3–4 are not about Jesus’ promotion or adoption as God’s Son. Both parts of the formula are regarding God’s Son (v. 3), but God’s Son in two manifestations: as servant and Lord, in humiliation and exaltation, in earthly ministry and heavenly reign.”  Scholarly proponents of pre-Pauline adoptionist Christology recognize this, and thus it is commonly argued that this phrase ἐν δυνάμει was added to the creed by Paul and is not a part of the original.  Bart Ehrman contends that “Paul may have wanted to add this phrase [‘in power’] because according to his own theology, Jesus was the Son of God before the resurrection, but he was exalted to an even higher state at the resurrection.”  The reasoning here, however, is rather circular. Simon Gathercole summarizes why: “So Paul incorporates an ‘adoptionist’ fragment in Romans 1. But hang on—Rom 1:3–4 is not adoptionist. But we can make it adoptionist if we remove ‘in power.’”  In other words, Ehrman’s argument assumes that the earliest Christians affirmed an adoptionist Christology and that the idea of Christ’s pre-existence developed later, and that the phrase “in power” ought to be disregarded as a Pauline interpolation since that would render the creed non-adoptionist (and we know that pre-Pauline Christianity was adoptionist… somehow).
James Dunn also rejects the idea that adoptionism was implied in the pre-Pauline tradition. He writes, “We should certainly beware of interpreting the formula itself in a rigidly antithetical way—Son of David in respect of his human birth, but Son of God in respect of his resurrection—not least because the idea of the royal messiah as also God’s Son was not unfamiliar to Jewish thinking. To that extent the formula remains within Jewish thought and hope and so reinforces Paul’s emphasis on the continuity between Israel’s hope and his gospel.”  Indeed, the Dead Sea Scrolls (esp. 4Q174) indicate that the Davidic Messiah could be regarded as the Son of God, and therefore this was not at all foreign to apocalyptic Jewish thinking. Dunn continues, “Yet, at the same time, we should not ignore the force of the phrase ‘appointed … as from the resurrection of the dead.’ It is clear from this phrase that for Paul the resurrection marked a decisive stage in Christ’s divine Sonship—not as marking its beginning (the possibility that this was implied in the earlier formulation is not strong and depends on reading ‘in power’ as a Pauline addition), but certainly as marking a significant ‘heightening’ or enlarging of its scope.” 
A further problem with the thesis that the original form of the creed contradicted Paul’s own theology, prompting him to amend it, is that it raises the question of why Paul would have used this creed at all. Michael Bird notes that “It is counter-intuitive for Paul to cite this creed as evidence of the common faith that he shared with his readers and then to amend it because it was christologically inadequate.” 
To summarize, while it is plausible that Romans 1:3-4 reflect a pre-Pauline creedal tradition, the arguments for this are too conjectural to develop further arguments from. It is also circular to suppose that Paul must have edited the creed to be consistent with his non-adoptionist Christology without any direct evidence of interpolation or, at the very least, independent reason to believe that pre-Pauline Christology was indeed adoptionistic. It also seems surprising that Paul would have used this creed at all if it so fundamentally diverged from his own Christology.
Bringing About the Obedience of Faith
Paul indicates that through Christ “we have received grace and apostleship to bring about the obedience of faith for the sake of his name among all the nations,” (Rom 1:5). This is the great commission that Jesus gave to the apostles, as well as those who would follow them – to “make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you.” (Mt 28:19-20). Indeed, the Old Testament had also prophesied that the Messiah would be “a light for the nations, that my salvation may reach to the end of the earth,” (Isa 49:6, c.f. Isa 11:10; 42:6).
What does Paul mean by “the obedience of faith?” Craig Keener notes that “Paul is clear from the beginning that genuine faith in Christ (itself obedience to the gospel; cf. 6:17) should, if carried out, produce a righteous lifestyle (see ch. 6). Paul probably returns to this crucial point in 16:26. Disobedience brings reproach on Christ (cf. 2:24); God saves a people for his “name,” that is, for his glory or honor. (Roman society had a keen sense of honor and shame, and would appreciate the importance of God’s honor.)”  Indeed, Paul stresses the importance of works that accompany saving faith many times in his letters. Paul instructs the Christians in Philippi to “work out your own salvation with fear and trembling,” (Phil 2:12). Elsewhere in Romans, Paul answers an objection that had been raised to his preaching: “What shall we say then? Are we to continue in sin that grace may abound? By no means! How can we who died to sin still live in it?” James likewise wrote, “What good is it, my brothers, if someone says he has faith but does not have works? Can that faith save him? If a brother or sister is poorly clothed and lacking in daily food, and one of you says to them, ‘Go in peace, be warmed and filled,’ without giving them the things needed for the body, what good is that? So also faith by itself, if it does not have works, is dead,” (James 2:14-17). Though Paul is often said to contradict James on the requirement of works for salvation, the soteriology of Paul and James is quite consistent on this point.
Called to Belong to Jesus Christ
Paul also mentions that the Roman Christians are among those who have been “called to belong to Jesus Christ” (Rom 1:6). This implies the doctrine of election, a tenant of Paul’s theology that he affirms elsewhere. For example, later in this same epistle, he writes, “For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified,” (Rom 8:29-30). Thus, for Paul, to be “called” is a guarantee that one will also be justified, and, having been justified, will also be glorified. Paul’s words also recall the words of Jesus, who said, “My sheep hear my voice, and I know them, and they follow me. I give them eternal life, and they will never perish, and no one will snatch them out of my hand,” (Jn 10:27-28). One also recalls the words of Acts 13:48, which, speaking of the gentiles, notes that, in response to Paul’s preaching, “as many as were appointed to eternal life believed,” (Acts 13:48).
Grace and Peace
Paul finishes this section with a customary greeting: “To all those in Rome who are loved by God and called to be saints: Grace to you and peace from God our Father and the Lord Jesus Christ,” (Rom 1:7). Whereas most letters of this time period contained a single word, χαίρειν, meaning “greetings” (see Jas 1:1), Paul by contrast also includes terms that are loaded with theological meaning. “Grace” (χάρις) refers to the unmerited favor that God has shown towards sinners. “Peace” (εἰρήνη) is the fruit of God’s grace — that is, as Paul will write later, “since we have been justified by faith, we have peace with God through our Lord Jesus Christ,” (Rom 5:1).
What does it mean to be a saint? To be a saint means to be “set apart for the gospel of God,” (Rom 1:1). Craig Keener notes that “Scripture portrayed Israel as ‘beloved’ (cf. 11:28), ‘called’ (cf. 11:29), and as ‘set apart’ for God (cf. 11:16). Paul readily applies all these titles to a majority Gentile congregation (cf. 1:13), since all who serve Israel’s rightful king (1:3–4) are grafted into Israel’s heritage (cf. 11:16–17). They, too, are special objects of God’s love (5:5, 8; 8:35, 39; and probably 15:30).” 
Paul in his letter will return to many of the topics that he touched on in his prologue. He will return to discuss the believers’ former slavery to sin in contrast to their new slavery to God (Rom 6:6, 16-22; 7:6, 25; 8:15; 12:11; 14:18; 16:18), their “calling” that was initiated by God (Rom 1:6-7; 8:28, 30; 9:7, 12, 24-26), and their being “set apart” for God (Rom 1:7: 6:19, 22; 8:27; 11:16; 12:1, 13; 15:16, 25-26, 31; 16:2,15). The Holy Spirit’s role in raising Jesus from the dead will also be returned to (Rom 8:11). The theme of God having promised the gospel through the prophets is also a recurring theme in Romans (Rom 4:13, 14, 16, 20, 21; 9:4, 8, 9; 15:8). Indeed, the gospel (εὐαγγέλιον) itself is a major theme of Romans, and Paul also speaks elsewhere in this letter of “what Christ has accomplished through me to bring the Gentiles to obedience – by word and deed,” (Rom 15:18). Paul’s opening words also set up a bookend with the close of the epistle, where he writes concerning the same themes: “Now to him who is able to strengthen you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery that was kept secret for long ages but has now been disclosed and through the prophetic writings has been made known to all nations, according to the command of the eternal God, to bring about the obedience of faith—to the only wise God be glory forevermore through Jesus Christ! Amen,” (Rom 16:25-27).
 James R. Edwards, Romans, Understanding the Bible Commentary Series (Grand Rapids, MI: Baker Books, 2011), 25.
 James D. G. Dunn, Romans 1–8, vol. 38A, Word Biblical Commentary (Dallas: Word, Incorporated, 1988), 6.
 Ibid., 6-7.
 Craig S. Keener, The IVP Bible Background Commentary: New Testament, Second Edition. (Downers Grove, IL: IVP Academic: An Imprint of InterVarsity Press, 2014), 426.
 James R. Edwards, Romans, Understanding the Bible Commentary Series (Grand Rapids, MI: Baker Books, 2011), 27.
 James D. G. Dunn, Romans 1–8, vol. 38A, Word Biblical Commentary (Dallas: Word, Incorporated, 1988), 7–8.
 J. A. Motyer, The Prophecy of Isaiah: An Introduction & Commentary (Downers Grove, IL: InterVarsity Press, 1996), 121.
 Craig S. Keener, Romans, New Covenant Commentary Series (Eugene, OR: Cascade Books, 2009), 20.
 John Ronning, The Jewish Targums and John’s Logos Theology (Grand Rapids, MI: Baker Academic, 2011), 102.
 Seth Postell, Adam as Israel: Genesis 1-3 as the Introduction to the Torah and Tanakh (Pickwick Publications, 2011), 129. Also see John Sailhamer, Genesis Unbound: A Provocative New Look at the Creation Account (Multnomah Books, 1996).
 Michael L. Brown, Answering Jewish Objections to Jesus Volume 3: Messianic Prophecy Objections (Baker Books, 2003), p. 43.
 John Ronning, The Jewish Targums and John’s Logos Theology (Baker Academic, 2011), 105-114.
 Craig S. Keener, The IVP Bible Background Commentary: New Testament (Downers Grove, IL: InterVarsity Press, 1993), Ro 1:4.
 Bart D. Ehrman, How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee (New York: HarperOne, 2014), kindle.
 Simon J. Gathercole, “What Did the First Christians Think about Jesus?,” in How God Became Jesus: The Real Origins of Belief in Jesus’ Divine Nature—A Response to Bart Ehrman, ed. Michael F. Bird (Grand Rapids, MI: Zondervan, 2014), 104.
 James R. Davila, “(How Can We Tell if a Greek Apocryphon or Pseudepigraphon has been Translated from Hebrew or Aramaic?” Journal for the Study of the Pseudepigrapha 15, no. 1 (2005).
 Bart D. Ehrman, How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee (New York: HarperOne, 2014), kindle.
 Simon J. Gathercole, “What Did the First Christians Think about Jesus?,” in How God Became Jesus: The Real Origins of Belief in Jesus’ Divine Nature—A Response to Bart Ehrman, ed. Michael F. Bird (Grand Rapids, MI: Zondervan, 2014), 106.
 Walter Schmithals, The Theology of the First Christians, trans. O. C. Dean Jr. (Louisville: Westminster: John Knox, 1997), 89–90.
 Gordon D. Fee, Pauline Christology: An Exegetical-Theological Study (Peabody, MA: Hendrickson, 2007), 544.
 Michael F. Bird, Jesus the Eternal Son: Answering Adoptionist Christology (Grand Rapids, MI: William B. Eerdmans Publishing Company, 2017), 14.
 Ibid., 12–13.
 Michael F. Bird, Jesus the Eternal Son: Answering Adoptionist Christology (Grand Rapids, MI: William B. Eerdmans Publishing Company, 2017), 19.
 James R. Edwards, Romans, Understanding the Bible Commentary Series (Grand Rapids, MI: Baker Books, 2011), 30.
 Robert Jewett, Romans: A Commentary (Minneapolis: Fortress, 2007) and Joseph Fitzmyer, Romans: A New Translation with Introduction and Commentary (New Heaven, CT: Anchor Bible, 1997).
 Bart D. Ehrman, How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee (New York: HarperOne, 2014), kindle.
 Simon J. Gathercole, “What Did the First Christians Think about Jesus?,” in How God Became Jesus: The Real Origins of Belief in Jesus’ Divine Nature—A Response to Bart Ehrman, ed. Michael F. Bird (Grand Rapids, MI: Zondervan, 2014), 105.
 James D. G. Dunn, Romans 1–8, vol. 38A, Word Biblical Commentary (Dallas: Word, Incorporated, 1988), 23.
 Michael F. Bird, Jesus the Eternal Son: Answering Adoptionist Christology (Grand Rapids, MI: William B. Eerdmans Publishing Company, 2017), 18.
 Craig S. Keener, Romans, New Covenant Commentary Series (Eugene, OR: Cascade Books, 2009), 21–22.
 Ibid., 22.