I offer a new deductive formulation of the Moral Argument for the existence of God which shows how one might argue for the conclusion that, if one affirms moral realism (traditionally understood as a metaethical view which acknowledges the existence of objective moral truths), one should affirm theism. The new formulation shows that these objective moral truths are either brute facts, or they are metaphysically grounded in an impersonal entity, a non-divine personal entity, or a divine personal entity i.e., God. (...) I illustrate how the alternatives to God can in principle be excluded based on the essential characteristics of those alternative hypotheses and of certain objective moral truths. I demonstrate that my deductive formulation is better than other formulations, and that it is helpful for future work on the Moral Argument. (shrink)