How on Earth Did Jesus Become a God?

Recently I have been doing some work on the Gospel of John and first-century Jewish monotheism. 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 divine?
There are many scholarly works that prove helpful in this discussion, but one of the best is the collection of essays by my doktorvater, Larry Hurtado, in his wonderful book, How on Earth Did Jesus Become God? (Eerdmans, 2005).