Lewis believes that readers are intelligent enough to deal not only with practical religion but with theology, although he acknowledges that those who have felt God’s presence may see dogmas and formulas as redundant and reductive. Nevertheless, Lewis states that we need to recognize how many similar (or even more profound) experiences have led to the development of theology, and to bear in mind that any single experience on its own is unlikely to provide a person with a path going forward. Furthermore, in a world in which people read about and discuss ideas, ignoring theology means being out of touch.

Lewis suggests that theology can help us understand the distinction between the popular conception of Jesus as an important moral teacher and the Christian idea of Christ. One of the core claims of Christianity is not simply that Jesus is the Son of God, but that through him, we also become the sons of God. While this is already true in a certain sense—God brought us into existence and looks after us—the Bible means something different when it uses this phrase.

To explain this, Lewis turns to the Nicene Creed, which states that Christ was “begotten, not created” and, moreover, that he was “begotten by his Father before all worlds.