One of the finest of Dick's 1960s works, "Palmer Eldritch" is a book brimful of superb ideas. Some are bitingly satirical (future colonists will relieve the excruciating boredom of their lives by entering the ideal world of Ken and Barbie analogue Perky Pat, making dolls and doll accessories the most prized items in the solar system). Some are sad (humans undergo a cosmetic process to accelerate their evolution, but sometimes the process goes awry). And some are just plain terrifying, particularly those ideas surrounding the evil messiah Palmer Eldritch, who returns from Proxima Centauri with a divine sacrament that just might grant eternal life.
Unlikely ever to be filmed, (though John Lennon and Timothy Leary reputedly tried to secure the rights), and unlikely to appeal to hardcore sci-fi fans on account of its playful treatment of religious themes, "Stigmata" is nonetheless a brilliant, thoughtful novel about the slippery nature of reality and the untrustworthiness of those who claim to be experts on the subject. The fact that it's so often overlooked is understandable, but for those who can be bothered it will more than reward your patience.