Those who think about time are thinking deeply. Those who think about God are thinking even more deeply still. To try to think about both at once is to press the very limits of human understanding. Undeterred, this is precisely the project which William Lane Craig sets for himself in this study: to try to grasp the nature of divine eternity, to understand what is meant by the affirmation that God is eternal, and to formulate a coherent doctrine of God's relationship with time. In this work, Craig brings together discussions in the philosophy of time and space, philosophy of language, phenomenology, philosophy of science, special and general relativity, classical cosmology, quantum mechanics, and so forth, with the concerns of philosophy of religion and theology, in order to craft a philosophically informed and scientifically tenable doctrine of divine eternity and God's relationship to time.