One thing to keep in mind is that even if you are a Christian who holds the theological belief that God became Jesus (as I do), there is still the need of giving an historical account of how Jesus became God, that is, of how, when, and why his followers began to think of him as in some way divine. This is what Ehrman's work is mostly concerned with, and he does a remarkable job tracing the various options available to first century Jewish monotheists for including Jesus within the identity of the one God. Contrary to what some have accused him of, he doesn't argue that belief in Jesus's divinity was a late invention. Instead, Ehrman believes that belief in Jesus as a divine being came very early in the Christian tradition, even before Paul.
In my view, the best contribution of the work comes in the first couple chapters where Ehrman shows us that while we may think of "divinity" and "humanity" as totally separate categories, in the ancient world (both pagan and Jewish) these distinctions were thought of more along a continuum. It was possible for human beings to become divine and for a divine being to become human, and Ehrman gives numerous examples from the Old Testament and ancient mythology to support this thesis.
His discussion of the "Angel of the Lord" in the Old Testament, and his subsequent argument that Paul and other early Christians thought of Jesus as God's chief angel, is a very provocative argument that, I must say, seems much more plausible than I originally thought it would be when he first suggested the idea. I look forward to following up on the scholarly work of Susan Garrett, whom he seems (based on his footnotes) to rely a great deal on for this argument.
In short, Ehrman's big contribution is to move the debate beyond just asking "Is Jesus God?" to asking "In what sense is Jesus divine?" Because the categories of divinity and humanity were more fluid and existed on something of a sliding scale in the ancient world, it was possible for Jesus to be declared a divine being early on, while still allowing room for him to become "upgraded" as theological reflection progressed over the centuries. Even though Jesus was declared to be in some way divine very early on, it is undeniable that in the centuries leading up to Nicea he began to be thought of in even more exalted and higher terms. (I would stress, again, that showing historical development in a theological belief doesn't necessarily invalidate that theological belief. There can, after all, be genuine development in theological knowledge, so just because a belief isn't the earliest belief doesn't mean it is a false belief.)
While there is much to learn from this book and much to praise, I also must say that I found his two chapters on the resurrection to be disappointing. Part of his main thesis is that it was the belief in Jesus's resurrection that kicked off the early Christian belief that Jesus was in some sense divine. While this makes a good deal of sense, and really isn't at all controversial, Ehrman for some reason feels the need to spend a good chunk of the book explaining why he thinks the resurrection didn't really happen. As has been pointed out by another NT scholar, this is largely irrelevant to his overall thesis, since it was the belief in the resurrection, not the resurrection itself, that started the Christian movement.
These are the only chapters in the book where I got the sense that Ehrman was being too one-sided and driven by a certain agenda in the way he presented the information. His dismissal of the burial tradition seemed to move very fast with some rather weak arguments, and this then became the primary basis for the denial of the empty tomb. He also spent a good deal of time explaining (or explaining away) why the disciples would have had visions of Jesus after his death (grief and guilt), and yet he never once addressed how this theory, while though plausible for the disciples, cannot at all explain how or why Saul, an enemy of the church, would have had such a vision.
One of my general frustrations with these chapters is that he did not interact at all with the arguments of N.T. Wright, who has authored one of the most massive and significant explorations of the resurrection yet. I also found myself scratching my head at some of his specific arguments. For example, Ehrman thinks that the empty tomb is a later invention without an historical basis, and played no role in the early belief in Jesus's resurrection. He believes that the visions of the Risen Jesus alone are sufficient to generate a belief in the resurrection of Jesus. One of the counterarguments to this (and a good one, in my opinion) is that visions alone wouldn't generate a belief in resurrection of the body of Jesus because there was no precedent in Jewish thought for the idea that one person could be resurrected before the end of the age at the general resurrection. Ehrman respond:
This too is an interesting argument, but it also is not convincing to someone who knows something about ancient beliefs of life and the afterlife. (203)
After this rather condescending remark (at least it seems that way to me), he offers three pieces of evidence for why believing in the resurrection of an individual in the present age would not be that big of a deal for ancient Jews.
First, he mentions that in the gospels we are told that Herod Antipas believed that Jesus was John the Baptist "raised from the dead." Therefore, this shows that such a belief could be entertained after all. This is his strongest example. It is indeed hard to know what to make of this, or how widespread this belief was. It does perhaps show that such a belief is possible, but it would too much to use this as evidence for a fairly widespread belief. His next two examples show that he is really reaching in trying to dismiss this counterargument.
Second, he points to the fact that it appears that some, perhaps many, in the late first century in the Roman empire believed that the Emperor Nero would return from the dead to get his revenge. This is fairly weak piece of evidence for his argument. First, the myth of Nero's return was dominantly understood to mean that Nero didn't really die and was hiding out in the East to return with an army. This obviously has nothing to do with a resurrection. While he was later believed to be an anti-christ figure who would come from hell to wreak havoc, it seems doubtful that this belief sheds much light on what was a live option for a first-century Jew regarding the afterlife.
Third, he points out that in the gospels Jesus raised people from the dead, so this shows it wasn't unthinkable to believe a person might come back from the dead. This is not only a weak argument, it is a completely irrelevant example for his argument. What is fascinating is that Ehrman himself, just two pages later, acknowledges that a miraculous resuscitation is not at all the same as a resurrection (since the latter involves the transformation into an immortal body, which obviously didn't happen to folks like Lazarus. He still had to die again.) Since he acknowledges this, I am left wondering why he tries to use this example the way he does.
This section left me with the impression that Ehrman was functioning as the mirror-image of the Christian apologists he frequently criticizes in these chapters for having a conclusion in mind and then only paying attention to evidence that supports that conclusion. It isn't hard to see that Christian apologists aren't the only ones stretching the evidence to fit a preconceived conclusion. Ehrman does well in showing how conservative Christian defenders of the faith often overplay certain elements to show they have "proved" Jesus was raised from the dead (his critique of the there-is-no-way-they-would-have-invented-the-women-at-the-tomb-unless-it-happend-that-way argument was pretty solid), yet the same argument could be applied to some of his argument as well.
All that to say, I thought it was overall a fascinating read and raised some great questions and explored some intriguing possibilities. It made me want to learn and think more about how ancients understood the divine/human continuum, and it made me even more aware of how much we have a tendency to retroject our own ways of seeing things on the texts we read. Ehrman also reminded us that sometimes modern scholarly constructs get in the way of us seeing the true importance and significance of ancient texts. For example, the way he reframed what many call "adoptionist" views of Christ as an "exaltation" view of Christ was very helpful in reminding us that perhaps the categories we use to organize information sometimes get in the way of seeing all the nuance and complexity that can be found.
It is truly amazing, that a person crucified two thousand years ago we Christians now identify with God. If anything, this work helps us see just how remarkable and dizzying such a belief really is.