This paper examines the relationship between the classical theistic conception of God and modal realism. I suggest that realism about possible worlds has unwelcome consequences for that conception. First, that modal realism entails the necessity of divine existence eludes explanation in a way congenial to a commitment to both modal realism and classical theism. Second, divine knowledge is dependent on worlds independent of the creative role and action of God, thereby suggesting a limitation on the nature of divine knowledge and on the nature of God's creative role. Third, modal realism indicates the existence of real, albeit non-actual, worlds of appalling evil threatening the classical conception of divine omnipotence and benevolence.