“Jesus went from being a potential (human) messiah to being the Son of God exalted to a divine status at his resurrection.” Bart D. Erhman How Jesus Became God
Christology, (Greek Χριστός, Khristós and -λογία,), is a branch of theology that concerns Jesus. The debate about “who” Jesus was and is has been and is one of the most controversial conundrums since his birth.
“When Jesus came to the region of Caesarea Philippi, He questioned His disciples: “Who do people say the Son of Man is?” They replied, “Some say John the Baptist; others say Elijah; and still others, Jeremiah or one of the prophets.”…“But what about you?” he asked. “Who do you say I am?” ” Matthew 16: 13-15
Since the time of Peter’s response, Jesus’ fellow Jews and those following him, before and after his death, have been trying to answer that question ever since. Aside from the gospels and letters by Paul and other apostles, as well as other non-canonical scriptures, early Christian leaders like Tertulian, Ignatius, Polycarp, Justin Martyr, Irenaeus, Clement of Alexandria, Origen, and Hippolytus wrote extensive responses to that question about Jesus’ identity. Most of their responses were, in fact, attempts to rebuke the writings and beliefs of others whose opinions and beliefs were actualized as movements or Christian communities. For more about these men, go to: https://www.bethinking.org/jesus/the-early-church-fathers-on-jesus
The historical christological doctrines which gained broad support were many and a few were definitively labelled as “heretical”: Docetism, Arianism, Nestorianism, and Monothelitiam. Go to this link for more information about these heresies: https://en.wikipedia.org/wiki/Christology
The following three lectures by Bart Erhman are his attempt to explain how Jesus became God.
From Throne and Altar to Discipleship 