Christianity?
Dead god on a stick? Zombie jesus? I'd sooner worship the Meltdown Madonna..
I mean, Slavs had a better idea. They worshipped the God of thunder, because thunder is badass and really impressive*. No zombies, crucifixions, or stuff like that needed. In fact, the reasons why Slavs are so widespread(I mean, consider central Europe and Russia.,,) is, that they were a downright decent bunch of tribals.
Instead of sacrificing war captives, they gave them some mild forced labor probably, and after a year or two, gave them a choice: join us and become a full member of the tribe, or go back home, no hard feelings..
*I love storms. All the power and noise, and entirely natural.. and the rain in summer is a blessing indeed.
Really... if there were, say, Followers of the Apocalypse from Fallout, I'd join them. Or a modern day Sparta, which'd probably be like living in a military, but hey, I like guns, exercise and wargames, so I'd fit right in I guess.
Nothing like that exists, so I guess I have to be content with being a loner.