I recently read Christopher Moore's comic Lamb and I approve.
Immediate reaction to a work claiming to present a lost Gospel -- especially a comic work -- is that its author will look for laughs at the expense of those who believe what is taught by the religion in question. Examples aren't hard to think of: Monty Python's Life of Brian comes to mind, trying to explain the conclusion that Mary, mother of Jesus, was concluded to have been a virgin because she refused to answer blunt questions about her sex life when posed by rude strangers. Some folks get worked up over that kind of thing.
Moore's Lamb avoids this by heaping the bulk of his irreverent and often obscene script onto the lap of Biff. Lest anyone stand tempted to attribute to this new character the virtues of other Biblical good guys, Moore introduces Biff by having an angel demand to know why he should be ordered to have such an a---ole write a new Gospel.
This is important to keep readers from inadvertently deciding he should be identified with the saints and apostles and becoming angry at the author's treatment. Most of the jokes, after all, depend on the reader having fairly conventional ideas about sex and bodily functions, and being easily surprised Jesus should have a lifelong buddy who is into hookers. The remainder of the humor is a series of just-so stories about the origin of Jewish consumption of Chinese food on Christmas, the invention of the pencil, the true origin of the theory of evolution, and the ultimate fate of the yeti. Biff is no saint, he's just a bystander -- and a loyal friend.
From the "action" standpoint, Moore actually gets the reader interested in the question whether Biff, while looking out for his buddy Jesus, is going to manage to botch the sacrifice and resurrection. Is he going to explain it all away with medicine, killing the miracle altogether, or is everything going to come out according to Canon? In my view this part of the story constitutes a thriller worth the trouble to experience the rest of the book to appreciate, even if you don't care for yetis or hookers. I nominate it into the running for the best part of the book.
Of some interest to people who know and like the New Testament is Moore's effort to "explain" Jesus' perspective on traditional Jewish religions matters by fabricating anecdotes to make them seem reasonable, human, and plausible.
Well, OK; not so much plausible. I mean, the last of the Yeti? But it's entertaining, especially if you like lowbrow humor. For a light and irreverent trip, and perhaps to stir more serious thoughts about what really did happen so many years ago, have a read.