This paper argues that Mormon cosmology plus the Mormon view of the origin of human persons results in an undercutting defeater for Mormonism. The approach is modeled after Plantinga’s evolutionary argument against naturalism. The first step is to show that Mormon cosmology is relevantly like naturalism. The second step is to show that the origin of human persons ins relevantly similar to naturalistic evolution so that it faces the same kind of defeaters as the conjunction of naturalism and naturalistic evolution.