The worst thing one can say about God is that He rules the world. This is, I think, the supreme blasphemy.
To say that God doesn’t exist or that He is not good (the first in all seriousness, the second maybe half serious, half joking), is not by far as outrageous as saying that He rules the world. By ruling I mean absolute control over everything that is happening. To say that God does not exist or that He is not essentially good, is to force reality into saying more than it is able to say. We do not see God, so concluding that He doesn’t exist is in a way based in empirical reality. Of course, it ignores the very real possibility that things we cannot see may actually exist.
We live a world in which the quantity of evil and suffering is about the same as the quantity of good and joy. To conclude that God is not good (the similarity between God and good is quite striking in English, but of course this is not the case in other languages), assuming that the world is His creation, is as much in tune with empirical reality as it is to say that He does not exist. But it commits just as much the sin of overstatement.
The world may be very well be God’s creation, but have a head of its own, thus providing a gap between the Creator and the creation. If the world is bad, it does not have to necessarily mean its Creator is also bad. Only when affirming that God rules the world is one implying that God is evil. So to say that God rules the world, in the manner implied by His omnipotence, is much worse than saying that God is not good. If saying that God not good is something more than plain contradiction in terms, than it must mean that this bad god is not almighty, because otherwise the world would be entirely bad. A bad god who is also omnipotent would not allow the world to be good, not even for the fun of it. But an all powerful good God would allow the world to be bad. This is because good is good enough to allow its opposite to exist. But evil is not good enough for this.
Thus, saying that God rules this world is to make Him responsible for every bit of insanity, injustice, evil and suffering that this world is drown into and, even worse, is to deny the most important thing in this universe and every conceivable universe: freedom. This world is a chaotic mixture of good and evil, circling in a chaotic not-so-merry-go-around. And in this chaotic movement fueled by freedom resides its mystery, its beauty and its justification.