The moral from commit genocide

Believers of monotheism often questioning atheist :If there is no god?How could we maintain our morals?

So their moral is from a jealous tyrant who make a species and then keeping to commit genocide.And their have moral just because they have to obey this tyrant who have power.

Oh ,I see.God is the ego of  tyrants and domestic violence parents ,and the function of monotheism is testing how loyal people could be toward this kind of psychos.