This paper develops an alternative to Dennett's meme-theoretic explanation for religious commitment. First I build an argument in defense of Dennett's position, drawing on a cultural evolution literature that he mentions but does not develop (Dennett 2006). Then I describe data that even this enhanced account leaves poorly explained. Next I draw on commitment signaling theory to produce an account that explains these puzzling data. I show how religious culture provides a pervasive example of human epistemic niche construction. An adaptationist analysis of religious culture exposes how the propagation of costly misunderstandings massively reduce the cognitive burdens of Machiavellian social complexity.