VALIS

From Wikipedia:

VALIS is a 1981 science fiction novel by Philip K. Dick. The title is an acronym for Vast Active Living Intelligence System, Dick's gnostic vision of one aspect of God.

It is the first book in the incomplete VALIS trilogy of novels, followed by The Divine Invasion (1981). The planned third novel, The Owl in Daylight had not yet taken definite shape at the time of the author's death.

 VALIS is a story of a man, named Philip (same as the author), and his journey to find God with his alter-ego, Horselover Fat. Most of the story is a narrative that disguises a set of theological ideals established by Dick. The major subject of this narrative is spirituality, as both the protagonist, his alter-ego, and the author (who are all essentially one and the same) are ostensibly obsessed with several religions and philosophies, including Christianity, Taoism, Gnosticism, and even Jungian psychoanalysis. They are searching for a cure for what he believes is simultaneously both a personal and a cosmic wound.

Synopsis:

VALIS begins with the attempted suicide of Horselover Fat’s friend Gloria, offered in a standard third-person point of view. Almost immediately, however, a first-person narrator interrupts to declare, “I am Horselover Fat, and I am telling this in the third person to gain much-needed objectivity.” This first-person narrator, named Philip K. Dick, is for all intents and purposes identical to the author of the book. As a result of a mystical experience involving the Christian fish symbol and a beam of pink light, Fat is convinced that the world as he sees it—that is, California in 1974—is in fact an illusion laid over Imperial Rome. This illusion is the product of an evil entity opposed by VALIS, the Vast Active Living Intelligence System, which—depending on Fat’s mood and who he is talking to—is either an alien intelligence, an immensely sophisticated mechanism, or an incarnation of pure living information.

Halfway through the book, the character Philip K. Dick has a dream that convinces him that much of what Fat says, if not strictly true, is at least not crazy. Even though Fat proposes that he is a sort of superimposition of a man who lived during the time of Jesus Christ and that through this man benevolent aliens have begun to communicate with him, Dick begins to take him seriously enough to argue that what Fat is seeing as a divine being is in fact himself in the distant future. Shortly after this, the three (four) of them go to a movie called Valis, which includes an experience much like Fat’s pink-beam epiphany. Believing that the film has encoded a message to him, Fat goes looking for its maker, whose daughter is an incarnation of Sophia, or wisdom. In her presence Fat and Dick are healed and made whole. They become one again.

Sophia dies shortly after this, and Fat separates from Dick once again. Fat searches for a new savior he believes is about to be born into the world. He comes back with the words KING FELIX, which Dick then sees in a television commercial. This provokes Fat to go searching again, and Dick himself remains in front of the television, watching carefully for the next signal from VALIS.

https://en.wikipedia.org/wiki/VALIS