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 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.
Existentialism isn't so atheistic that it wears itself out showing that God doesn't exist. Rather, it declares that even if God did exist, that would change nothing.
The idea that God is an oversized white male with a flowing beard, who sits in the sky and tallies the fall of every sparrow is ludicrous. But if by 'God,' one means the set of physical laws that govern the universe, then clearly there is such a God. This God is emotionally unsatisfying... it does not make much sense to pray to the law of gravity.