I heard the following quotation on the radio¹ and, Lewis fan that I am, it was new to me.

But typical of his thought.

I haven't the book from which it was taken, a collection, so I scoured the internet² for snippets and pieced it together³:

The heart of Christianity is a myth which is also a fact.

By becoming fact it does not cease to be myth: that is the miracle. I suspect that men have sometimes derived more spiritual sustenance from myths they did not believe than from the religion they professed. To be truly Christian we must both assent to the historical fact and also receive the myth (fact though it has become) with the same imaginative embrace which we accord to all myths. The one is hardly more necessary than the other.

A man who disbelieved the Christian story as fact but continually fed on it as myth would, perhaps, be more spiritually alive than one who assented and did not think much about it . . .

We must not be ashamed of the mythical radiance resting on our theology. We must not be nervous about 'parallels' and 'Pagan Christs': they ought to be there - it would be a stumbling block if they weren't. We must not in false spirituality withhold our imaginative welcome.

¹ "Media: Friend or Foe? (Part 4 of 5)", Stuart McAllister, guest speaker, "Just Thinking" Broadcast, Ravi Zacharias International Ministries, air date 2/15/07

² My scouring turned up more delightful quotes at the ND Center for Ethics & Culture.

³ And then found the entire thing here, page 67.