Nimbu, an ex-Muslim from Pakistan, writes:
Well who are God's enemies? I'm confused. People that worship idols, say Hindus, are they God's enemies? What about people that worship any god but yours...are they God's enemies? If Jesus is God, does that make everybody that doesn't believe in him, God's enemies? What about Atheists (and I'm one), are they God's enemies? If so many people are God's enemies, and all 3 books teach us to destroy God's enemies, what to do? ...
I just don't understand how any human can kill a defenseless woman, child, old person, or even a dog. The only thing that makes sense is that these people were operating on God's command. If that's what a god would want, I'll gladly take my place in hell. It can't be any worse than a god that wants you to kill innocent children, whose only crime was being born, accidentally to another religion.
People don't need to believe that they are under orders from gods to participate in genocide or to kill children, but it helps. Few humans are such extreme sociopaths that, after being raised in a relatively healthy society, they could commit atrocities without much guilt or hesitation. People have to be convinced that repeated acts of extreme violence and cruelty are justified — so justified that all normal standards of human ethics and decency should be ignored.
Orders from God are among the strongest and most effective sorts of justification that can be offered. Religious theists can't deny this, either, because the three monotheistic faiths of Judaism, Christianity, and Islam revere a man precisely because he was willing to ignore normal standards of morality to fulfill the orders of God. Abraham is regarded as the model of "faith" for many religious theists because he did the "right" thing, which was try to murder an innocent child when told to do so by God.
One more idea is worth thinking about: in the religions where people are more likely to be instructed to kill on orders from a god, this same god is commonly described as being in control of the universe. Aside from raising the question of why this god isn't doing its own dirty work, this doctrine also suggests that no one is "accidentally" born into the "wrong" religion. If such a god wanted people born into the "right" religion, they would be — and this implies that these people were predestined to be slaughtered for their false beliefs even before they were born.