I just read a new book my Michael Bird, Jesus the Eternal Son: Answering Adoptionist Christology, Eerdmans. I think it is scheduled for release later this year by the good folks at Eerdmans Publishing.
Adoptionism was a second and third century “heresy” that has persisted in theological corners to today. Adoptionism claims that Jesus was a human being and not inherently divine. He acquired divine status as God’s Son sometime during his earthly life. Some say it happened at his birth, others his baptism, still others at this resurrection. One way to say it is that Jesus was not the Son of God but he became the Son of God. His elevation from human to divine status is often considered the default Christology of the Ebionites, Theodotians, and Paul of Samosata. A number of modern scholars (Knox, Dunn and Ehrman) think it was also the most primitive form of Christology expressed in texts like Rom 1:3-4 and Acts 2:36. Only later, do they say, that a fully incarnational Christology emerges.
In this brief and compelling book Michael Bird challenges those scholars who think the earliest recoverable Christology was adoptionism. Instead he proposes that the earliest Christologies formed a pattern of convictions and practices which featured Jesus at the center of Christian devotion. Only later, in the second century among the Theodotians, did adoptionism emerge full scale in debates over select texts and how they should be interpreted. A careful answer to the perennial question: who was/is Jesus?