An entertaining and good read, but a little bit to soft sometimes in my opinion.
It’s an interesting idea to show the life of Jesus from a comical standpoint, especially the parts of it which are not shown in the bible (i.e. between birth and when he starts to show his "powers"). Most of the book is entertaining, but I would have preferred if the whole story would’ve been more satirical. More often than not the author has chosen the easy joke, when a more "critical" (i.e. "jokes" questioning religious believes) comical point would’ve been possible. So I can’t understand some reviews I saw of the book, where the reviewers are speaking of blasphemy. I would say it’s obvious that the author tried to not hurt anyone’s feelings or believes. One sign for the intention by the author to not ridicule Jesus too much is in my opinion, that Jesus most of the time is the sidekick for Biff’s puns and jokes, although Jesus is the contemporary "star". To say it frankly : Whose faith is shaken by this story isn’t really a believer.
Like I said above, most of the book is entertaining, but somehow the last part, dealing with the time where Jesus is crucified, is extremely serious compared to the rest of the book, so that it feels separated from the rest in some way. Of course it’s not a laughing matter on first sight, but the author doesn’t shy away from puns and jokes in the rest of the story, so why there ?
The characterizations are good. Biff can be annoying sometimes, but all in all he’s a likeable character. Concerning Jesus it’s kind of a shame that this "Gospel" isn’t part of the bible, it would give Jesus Christ a lot more personality if it would be shown that he had his faults and weaknesses.
All in all a book I would recommend, if your searching for a book with a lot of humor in it. It’s not really criticizing Christianity, it’s just showing the "Messiah’s" life from a different stand point.