Valis

Valis is the first book in Philip K. Dick’s incomparable final trio of novels (the others being are The Divine Invasion and The Transmigration of Timothy Archer ). This disorienting and bleakly funny work is about a schizophrenic hero named Horselover Fat; the hidden mysteries of Gnostic Christianity; and reality as revealed through a pink laser. Valis is a theological detective story, in which God is both a missing person and the perpetrator of the ultimate crime.
The fact that what Dick is entertaining us about is reality and madness, time and death, sin and salvation–this has escaped most critics. Nobody notices that we have our own homegrown Borges, and have had him for thirty years. –Ursula K. Le Guin, New Republic