We conclude Lewis's discussion of the problem of the similarity but incongruity of the story of Jesus with the Pagan stories of dying and rising gods. Again, from chapter 14, "The Grand Miracle," from Miracles; a Preliminary Study.
Now if there is such a God and if He descends to rise again, then we can understand why Christ is at once so like the Corn-king and so silent about him. He is like the Corn-king because the Corn-king is a portrait of Him. The similarity is not in the least unreal or accidental. For the Corn-king is derived (through human imagination) from the facts of Nature, and the facts of Nature from her Creator; the Death and Rebirth pattern is in her because it was first in Him. On the other hand, elements of Nature-religion are strikingly absent from the teaching of Jesus and from the Judaic preparation which led up to it precisely because in them Nature's Original is manifesting itself. In them you have from the very outset got in behind Nature-religion and behind Nature herself. Where the real God is present the shadows of that God do not appear; that which the shadows resembled does. The Hebrews throughout their history were being constantly headed off from the worship of Nature-gods; not because the Nature-gods were in all respect unlike the God of Nature but because, at least, they were merely like, and it was the destiny of that nation to be turned away from the likenesses to the thing itself.
Lewis had much more to say about "the Grand Miracle," both before the passages I quoted and after. And much more to say about miracles, in general. I recommend his book highly.