But it is God "up there" who commands them to do these things? Maybe they are simply using God as an excuse to perpetrate purely human crimes, to "sugar-coat" acts of purely human libido dominandi and moral turpitude.
Certainly I believe that is the case with Islamic Jihadism.... I also believe that to have been the case WRT the Spanish conquistadors....
The case of Israel is seemingly different. But I would leave the elaboration of that issue to Jewish scholars, not having the competence myself.
The fact remains that those murderous societies are not/were not atheists. So believing in God obviously does not necessarily enhance one’s moral sophistication.