commitment

I have no explanation for your question. The fact that it is true is reason enough to do so. If that is not reason enough, then for any explanation I offer you can ask what the explanation is for it. It is like asking whether action X is moral, why should I do it, or whether action Y is immoral, why not do it. The mere determination that an action is moral or not is not sufficient to establish that there is an obligation to do it or to refrain from it. “God is evil” is an oxymoron. But beyond that, if God were evil I suppose we too would think differently and perceive/judge morality differently, so your question cannot be answered.