The big bang cosmological theory is relevant to Christian theism and other theist perspectives since it represents the universe as beginning to exist ex nihilo about 15 billion years ago. This paper addresses the question of whether it is reasonable to believe that God created the big bang. Some theists answer in the affirmative, but it is argued in this paper that this belief is not reasonable. In the course of this argument, there is a discussion of the metaphysical necessity (...) of natural laws, of whether the law of causality is true a priori, and of other pertinent issues. (shrink)