Last Updated September 5, 2023.
The Great Divorce by C. S. Lewis is something of his philosophical perspective on eternity transformed into a brief novel. He takes a few liberties with Christian theology (particularly the idea that no one can pass from Hell to Heaven and that no one can enter Heaven after they have died and been judged) to illustrate his greater points.
The beginning of the story describes people waiting for a bus in a dingy city, described much like an eternally-spreading metropolis styled after London. The characters describe their petty and desolate lives, as well as the loneliness and dissatisfaction they feel. They believe themselves to be in purgatory, awaiting judgment, and that this bus will take them to be judged. When it finally arrives, however, they are taken to the gates of Heaven—a lush, beautiful paradise—where they meet a poet (George Macdonald) who describes to them the nature of Heaven.
The characters realize they are essentially ghosts in the more real world that is Heaven. They pass through the trees and rocks and realize that this world is permanent and strong while they are weak and fading. The poet shows them from whence they have come (a small, nearly invisible crack in the ground), revealing their eternity to be Hell which, for all its seeming immensity, is inconsequential in comparison to Heaven's vastness.
While they are there, they are offered the chance to be freed from sin and enter into Heaven for eternity. One man, burdened by lust—which is represented by a lizard on his shoulder—takes the offer, killing the lizard so that he can be freed from it. He gradually becomes more solid as the lizard morphs and transforms into a mighty stallion that carries him into eternity, illustrating that our vices on Earth (and in Hell) are simply perversions of our true nature, things that are gifts from God to improve and purify us.