I’m a little surprised that the entirety of the kerfuffle that this book seems to have kicked up (at least as far as I’m aware) was an moronic challenge from a Fox News idiot.
Now, any realistic review should note that this book is doing a lot of extrapolation—as Aslan himself notes, the historical record on Jesus of Nazareth is spectacularly minimal. However, the few facts we have, when placed in the historical context—of which we have much more of a record—suggest that the constituency and central tenets of the bevy of sects that hold Jesus as their central focus are far removed from anything he intended.
In fact, the impression I was left with was that the most fundamental author of Christianity is most likely Paul of Tarsus. That seems a somewhat radical proposition in most actual Christia circles.