For Lewis, Christianity’s assertion of the reality of miracles is not an account of random divine interpositions strewn haphazardly into the ordered system of nature; rather, the whole account of Christian miracles through the ages is centered on one singular miracle. That miracle is the incarnation—the Christian term for the doctrine which says that God became man in the person of Jesus Christ. Every other miracle, both those which occurred historically before the incarnation and those which came after, were oriented towards this centrally important miracle. “There is no question in Christianity of arbitrary interferences just scattered about. It relates not a series of disconnected raids on Nature but the various steps of a strategically coherent invasion” (173). Every miracle is connected to the narrative of God becoming man for the redemption of humanity, either in preparation for that event or in witness to it. The story of the incarnation is what pulls together into a single narrative the otherwise disparate parts of the grand story of God and humanity.

Lewis also deals with the way that the broad outlines of the story of Jesus—descent and ascent, dying and rising again—are also features of many mythological nature-gods throughout the ancient world.