The invention of Sin

[timelets]

Sin"—for that is the name of the new priestly version of the animal "bad-conscience" (the inverted cruelty)—has up to the present been the greatest event in the history of the diseased soul: in "sin" we find the most perilous and fatal masterpiece of religious interpretation. Imagine man, suffering from himself, some way or other but at any rate physiologically, perhaps like an animal shut up in a cage, not clear as to the why and the wherefore! imagine him in his desire for reasons—reasons bring relief—in his desire again for remedies, narcotics at last, consulting one, who knows even the occult—and see, lo and behold, he gets a hint from his wizard, the ascetic priest, his first hint on the "cause" of his trouble: he must search for it in himself, in his guiltiness, in a piece of the past, he must understand his very suffering as a state of punishment.
...
The sick man has been turned into "the sinner"—and now for a few thousand years we never get away from the sight of this new invalid, of "a sinner"—shall we ever get away from it?—wherever we just look, everywhere the hypnotic gaze of the sinner always moving in one direction (in the direction of guilt, the only cause of suffering); everywhere the evil conscience.

--- F. Nietzsche, Genealogy of Morals. Third Essay, 20.