Adoptionism or dynamic monarchianism is the belief that Jesus has not existed as God’s Son from all eternity, but became God’s Son at his baptism, resurrection, or ascension. Adoptionism is even more unbiblical than Arianism which at least affirms the pre-existence of Christ. Adoptionists normally reject the virgin birth of Christ and assert that Jesus was merely a man who became God’s Son. Many adoptionists reject the authority of the Gospel of John and any New Testament writings which they believe reflect a later more fully developed Christology. The Ebionites of the second century were an early adoptionist group who rejected the writings of Paul and believed that Jesus was only a prophet of God and not God himself. Paul of Samosata and Theodotus of Byzantium were two of the leading adoptionists condemned as heretics by the early church. The Socinians attempted to revitalize adoptionism and were followed by a large portion of liberal scholarship. The New Testament scholar James D. G. Dunn is a modern example of an adoptionist who rejects the pre-existence of Christ.
Adoptionism errs by denying the authority of all of Scripture and misunderstanding those passages which teach on Christ’s baptism, resurrection, and ascension. Because they do not believe Jesus is both fully God and fully man, they are unable to understand those passages which teach on the exaltation of Christ. For example, some adoptionists argue that because Paul says the Father has bestowed on Jesus “the name that is above every name,” he became God’s Son when he was exalted to his right hand and has not been his Son from all eternity (Phil 2:9). But the bestowing of the name Yahweh on the Son is the declaration and vindication by the Father of what has been eternally true of the Son in contrast to his rejection by man. It is not the beginning of his sonship or deity, but the declaration of it. As God, the Son has authority over all things. But as a man, he must be given the authority to rule all things by the Father (Matt 28:18). And that is what happened at his exaltation. For the first time ever, a man enters into God’s presence on the basis of his own righteousness (Ps 24:3-10). It is a man who sits on the throne of God. Both adoptionism and Arianism are unable to distinguish between the deity and humanity of Christ and are unwilling to believe that both could be present at the same time in the person of Christ (Col 2:9).
Epiphanius reports that the Ebionites, an early adoptionist sect, rejected the virgin birth of Christ (Panarion 30.2.2). They continued the traditions of the Judaizers and practiced all of the laws of Moses. Like the Judaizers Paul fought against in Galatians, they separated themselves from Gentiles and viewed them as unclean (30.2.3). Some of them believed that Christ was a spirit who appeared in the form of Adam or was Adam himself (30.3.3-4). They made a distinction between the man Jesus and the spirit who is Christ: “The Spirit – that is, the Christ – came to him and put on the man called Jesus” (30.3.6). They believed that Jesus became the Christ when the Spirit anointed him (30.29.6). The Ebionites were divided as to whether Jesus was merely a man who became God’s Son or a pre-existent spirit: “Ebion himself did at one time, by saying that he originated as a mere man from sexual intercourse. But at other times the Ebionites who derive from him say that Christ has a heavenly power from God, ‘the Son,’ and that the Son puts Adam on and takes him off when convenient” (30.34.6). They rejected the writings of Paul and appear to be the first group of people to try to drive a wedge between Jesus and Paul:
“Nor are they ashamed to accuse Paul here with certain fabrications of their false apostles’ villainy and imposture. They say that he was Tarsean – which he admits himself and does not deny. And they suppose that he was of Greek parentage, taking the occasion for this from the (same) passage because of his frank statement, ‘I am a man of Tarsus, a citizen of no mean city.’ They then claim that he was Greek and the son of a Greek mother and Greek father, but that he had gone up to Jerusalem, stayed there for a while, desired to marry a daughter of the high priest, and had therefore become a proselyte and been circumcised. But since he still could not marry that sort of girl he became angry and wrote against circumcision, and against the Sabbath and the legislation” (30.16.8-9).
Of course, this is a hilarious narrative that has no basis in history or Paul’s writings. It is a fictional story created to justify their rejection of Paul’s writings which the early church always considered to be Scripture (2 Pet 3:16; 1 Clem 47:3). For a refutation of those who try to drive a wedge between Jesus and Paul, I recommend this documentary.