One of the themes that looms large in the writings of C.S. Lewis is myth. As a young atheist, Lewis assumed that the Christian story of Jesus was just one more religious myth (a fiction) among others. But, as Lewis continued to think and reflect and journey toward the Christian faith, he began to ponder instead of how the significance of myth might make a case for Christianity.
Lewis struggled with all the various myths, from different times and places, of a dying and rising god. Initially, he took a history of religions approach to Christianity, using these myths as proof that the story of the dying and rising of Jesus was just one more fiction. But then, he began to wonder if such an approach to myth was in actuality getting at the problem from the wrong direction. What if these various dying and rising god myths were in actuality "unfocused revelation," a kind of vague divine truth placed upon the human imagination? What if such unfocused revelation were one way God was preparing the world for myth to become fact in the coming of Jesus Christ?
Lewis came to believe that Incarnation was the place where myth and history came together in a focused or decisive revelation of God. Myth was, therefore, not something to be taken lightly because it was not historical. Such a view of myth by its own definition was a myth. Myth instead expressed inadequately what God would bring into focus over time in history.
This means two things: First, myths are important and must be taken seriously. They must not be rejected because they are not historical in nature. Second, myths are significant precisely because, at some point, the myth becomes history. If it fails to become history, it fails to be complete, and its truth fails to come into focus. In other word, myth becomes significant because it touches us in time and space.
Thus the importance of the different myths of the dying and rising god is found when those myths become history in Jesus Christ. To say, therefore, that Jesus' death and resurrection are to be understood only as metaphical or symbolic denigrates the significance of myths and the crucial necessity of the focused revelation of the life and work of Jesus Christ, where myth and history come together.