Believing that traditional Christian theism implies there is something epistemically wrong with religious unbelief, I examine John Calvin’s claim that everybody would believe in God if it weren’t for sin. I show why this claim ought to be more common than it is; develop it in terms of our naturally having certain reliable epistemic sets; utilize that development to specify exactly what is wrong with unbelief; and then argue that even unbelievers have some reason to think it is true.
