How did Jesus become a God?

From an an interesting review of How on Earth Did Jesus Become a God? by Larry Hurtado. Did an understanding of Jesus' divinity evolve over time in the early Church or was it there from the beginning?

Anyone who explores the high Christology in John is forced to ask how it would have (or could have) emerged within a monotheistic context.  How could early Jews have believed in the one true God of Israel, and also have believed that Jesus was also divine? ....

Early Christians drew a sharp line between their worship of Jesus and all the other pagan gods of the Greco-Roman world. Jesus was not simply a new addition to a pantheon of gods they already believed in, but was considered to be the only God rightly deserving of worship. ....

The exclusive nature of such worship is monotheistic at the core and suggests a Jewish origin, not a pagan-Gentile one. It is such remarkable devotion to Jesus, within a monotheistic context, that demands some sort of serious historical explanation. Hurtado declares, “But it was a major and unprecedented move for people influenced by the exclusive monotheistic stance of Second-Temple Judaism to include another figure singularly alongside God as the recipient of cultic devotion in their worship gatherings” ....

Hurtado concludes, therefore, that the earliest devotion to Jesus was in some sense “binitarian.” Christians worshiped Jesus not as a second god, but worshiped him alongside the one true God of the Jews. Such a radical and astounding “mutation” within early monotheistic Judaism cannot be accounted for, argues Hurtado, by the evolutionary model (or, for that matter, most other current models). ....

Overall, this volume by Hurtado continues to expand his already compelling argument that worship of Jesus was a remarkably early innovation that demands rigorous historical investigation. ....

...[H]e has succeeded in shifting the terms of the debate over the origins of Christianity and the nature of the historical Jesus. Instead of getting drawn into endless discussions about historical sources, redaction criticism, and the like, Hurtado has refreshingly streamlined the discussion by asking simple questions about the origins of the beliefs and practices of early Christians. Such beliefs and practices cannot simply be observed by the modern scholar but they demand historical explanations for their existence. It is at this point that the biblical explanation (early Christians experienced the resurrection of Jesus) shows itself to be the most compelling. [more]

How on Earth Did Jesus Become a God? | Canon Fodder