Modern analytic philosophy of religion has become increasingly interested in the dogmatic substances of Christian theology. I argue that the doctrine of the Trinity provides an instance of the importance of dogmatic formulation for an appreciation of the philosophical aspect of the Christian concept of God. The starting point of my discussion is the recent defence of pantheism by Michael Levine, and his discussion of Neoplatonist and German Idealist models of deity. Both metaphysical theism and the alleged Neoplatonic metaphysical generalogy of pantheism are considered with particular reference to St Augustine's account of creation in the "Confessions". Just as it is impossible to distinguish the purely philosophical from the purely dogmatic concept of God, one cannot give an adequate modern account of theism without a rigorous and sensitive treatment of the historical models. The issue of pantheism shows how a misunderstanding of the meaning of concept of 'unity' can distort our view of theism as a model of deity.