The atheist who read MacDonald on a train

C.S. Lewis is seventeen years old and a convinced atheist when he reads George MacDonald's Phantastes on a train and finds, as he would later put it, that the book had baptized his imagination.

He does not become a Christian. But something changes in the texture of his experience — a quality of holiness in MacDonald's fantasy world that he cannot account for and cannot dismiss.

The journey from that train ride to conversion takes some fifteen years. It passes through his friendship with J.R.R. Tolkien and Hugo Dyson, through their famous late-night conversation on Addison's Walk in September 1931 in which Tolkien argues that the gospel is the one true myth — the very story the human imagination has always strained toward, now made fact in history.

Lewis is converted in two stages. First to theism, in 1929 — kneeling alone in his room at Magdalen College, by his own account the most grudging and downcast believer in the whole of England. Then, two years later, to belief in Christ: days after the late-night walk with Tolkien, riding to Whipsnade Zoo in the sidecar of his brother's motorcycle. When the motorcycle set off, he later wrote, he did not yet hold that Jesus Christ was God's Son; by the time the zoo came into view, he found that he did.

He goes on to write the most widely read Christian apologetics of the twentieth century: Mere Christianity, The Problem of Pain, The Screwtape Letters, The Chronicles of Narnia. He reaches people who will not read a sermon or attend a church, who encounter the faith through a lion and a wardrobe.

The baptized imagination, decades later, baptizing millions of others.

Lewis's most famous line about faith is not about certainty. It is about light.

What he said, in effect, was that he trusted Christianity not merely as a thing he could look at directly, but as the light by which everything else came into view.

This is not the argument from evidence to conclusion. It is the argument from illumination — the recognition that the Christian framework makes the rest of experience more intelligible, not less. That with it, things that were previously inexplicable become comprehensible. That by its light, other light becomes visible.

Lewis found this on a train at seventeen, in a fantasy novel, before he had any theological language for it. His imagination recognized something true before his intellect could name it.

What have you seen that you cannot fully explain apart from the faith? And what does that seeing suggest about the source of the light?