This paper evaluates the role that evolutionary psychology can play in examining the rationality of faith in the Christian sense. It is argued that because evolutionary psychology enables us to understand human nature, it can help us understand what faith is. I argue that faith is not a universal human instinct that all religions tap into. Rather, we must understand how the early Christian community used the basic building blocks provided by human nature in a particular way. It is argued that it is a misunderstanding of the nature of faith to assert that faith is intrinsically irrational. However, evolutionary psychology cannot tell us whether or not faith is rational.