Doubt as sin. -- Christianity has done its utmost to close the circle and declared even doubt to be sin. One is supposed to be cast into belief without reason, by a miracle, and from then on to swim in it as in the brightest and least ambiguous of elements: even a glance towards land, even the thought that one perhaps exists for something else as well as swimming, even the slightest impulse of our amphibious nature - is sin! And notice that all this means that the foundation of belief and all reflection on its origin is likewise excluded as sinful. What is wanted are blindness and intoxication and an eternal song over the waves in which reason has drowned.
Friedrich Nietzsche, Daybreak , s. 89.