It is simple, like you. I'll spell it out for you so your simple mind can comprehend it;
You say god did not stop it because people do not believe in him, I simply stated that if there was a god, then he should have stopped it, or been able to stop it, but since he did neither, than if he does exist ( which he does not) then he is evil as Dan pointed out, or the more logical conclusion, he does not exist.
Occam's razor, in more simple terms for you to understand: All things being equal, the most simple resolution is often the truth.
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