Adoptionism

Adoptionism is a view held by some early Christians that Christ was born a human only, and was not divine until his baptism, at which point he was adopted as the Son by God the Father.

It is one of two main forms of monarchianism; the other is modalism. Adoptionism was an early attempt to explain the relationship between Jesus Christ and God the Father, while maintaining Christianity's monotheism. It differs significantly from the doctrine of the Trinity that was later adopted by the ecumenical councils.

One of the early exponents of Adoptionism was Theodotus of Byzantium. The belief was declared heretical by Pope Victor I.