Narnia explained

A friend (thanks, Karl) saw this on Facebook, sourced it, and sent it on to me. C.S. Lewis in a 1961 letter:

Since Narnia is a world of Talking Beasts, I thought He [Christ] would become a Talking Beast there, as He became a man here. I pictured Him becoming a lion there because (a) the lion is supposed to be the king of beasts; (b) Christ is called "The Lion of Judah" in the Bible; (c) I'd been having strange dreams about lions when I began writing the work. The whole series works out like this.

The Magician's Nephew	tells the Creation and how evil entered Narnia.
The Lion, the Witch and the Wardrobe	the Crucifixion and Resurrection.
Prince Caspian	restoration of the true religion after corruption.
The Horse and His Boy	the calling and conversion of a heathen.
The Voyage of the "Dawn Treader"	the spiritual life (specially in Reepicheep).
The Silver Chair	the continuing war with the powers of darkness.
The Last Battle	the coming of the Antichrist (the Ape), the end of the world and the Last Judgement.