Friedrich Nietzsche Quote
As is well known, the priests are the most evil enemies — but why? Because they are the most impotent. It is because of their impotence that in them hatred grows to monstrous and uncanny proportions, to the most spiritual and poisonous kind of hatred. The truly great haters in the world history have always been priests; likewise the most ingenious haters: other kinds of spirit hardly come into consideration when compared with the spirit of priestly vengefulness.
Essay 1, Section 7. - On the Genealogy of Morality (1887)