“You ask me my religious views: you know, I think, that I believe in no religion. There is absolutely no proof for any of them, and from a philosophical standpoint Christianity is not even the best. All religions, that is, all mythologies to five them their proper name are merely man’s own invention – Christ as much as Loki. Primitive man found himself surrounded by all sorts of terrible things he didn’t understand – thunder, pestilence, snakes etc: what more natural than to suppose that these were animated by evil spirits trying to torture him. These he kept off by cringing to them, singing sons and making sacrifices etc. Gradually from being mere nature-spirits these supposed being[s] were elevated into more elaborate ideas, such as the old gods: and when man became more refined he pretended that these spirits were good as well as powerful. Thus religion, that is to say mythology grew up.”

Walter Hooper, ed., The Collected Letters of C. S. Lewis: Family Letters 1905-1931 (San Francisco: Harper, 2004), 230-31; written to friend, Arthur Greeves, possibly dated 12 October, 1916.