Ich heiße das Christentum den Einen großen Fluch.
This quote is from Nietzsche's The Antichrist (1888):
"I call Christianity the one great curse
...the one great intrinsic depravity, the one great instinct for revenge for which no expedient is sufficiently poisonous, secret, subterranean, petty - I call it the one immortal blemish of mankind."