Atheists can you really say God does not Exist?

I have read many religious books, the quran, the bible and the hindu texts, and I can only conclude that if their gods do exist, he is a jerk, bloodthirsty, ist and racist. Nature does not prove or disprove god, there are good things as well as bad things, and if the good proves god, then what about the bad? The possibility of a god who has created us, who is watching over us is only valid if he is incompetent.