The Screwtape Letters (1942), is a satirical novel Lewis wrote, supposedly in defense of Christian faith, in which the character Screwtape, an experienced devil, instructs his young charge, Wormwood, on effective strategies for tempting a human being toward damnation. The book is celebrated for hits witty use of ironic inversion: for example, God is “the Enemy,” Satan is “Our Father Below,” hierarchy becomes “Lowerarchy.”

Ironic inversion, huh? Sounds like up is down, left is right and nothing is what it seems. Satanists masquerade as Christians in order to preach to their own cult while simultaneously accomplishing a "soft-sell" of paganism to a naive and adoring public.