The two-doofus comedy probably goes back to ancient times, so why not set it there? The always-funny Michael Cera and the frequently-funny Jack Black join forces like Hope and Crosby in an only intermittently-funny movie that is just a series of sketches set in ancient days — prehistoric, Biblical, Roman, and Egyptian. Cera plays Oh, a gatherer, and Black is Zed, a hunter. They are pals who are evicted from their stone-age village and wander off, meeting up with Cain and Abel, Abraham and Isaac, and the residents of Sodom. In yet another “what was the MPAA thinking” moment, the film has been assigned a PG-13 rating, despite jokes about incest, circumcision, orgies, castration, and ingestion of human waste.

The juxtaposition of modern sensibility and prehistory provides some funny contrasts. Oh and Zed are amazed to see their first wheel and when they ride in their first vehicle they raise their arms as though they were in a roller-coaster, even though it cannot keep up with a guy strolling alongside. And then they get their first carsickness. Some things are eternal — like insecurity with the opposite sex, bullies, and the bad guys having English accents. And it is fun to see a modern perspectives combined with ancient situations.

But more doesn’t work than does. Cain does not just kill Abel; he pounds him — and any potential for humor — into the ground. It isn’t enough that a pagan priest be corrupt and gay; he has to be hairy. The movie is too spotty to be comic and too listless to be heretical. There’s no point to it, just a series of gags — in both senses of the word.