You lost me. Why doesn't the fact that society has developed an innate feeling of "murder is wrong" make it immoral?
You don't understand what the word innate means. It means inborn, natural, inextricably tied with the nature of the thing itself, part of the DNA. Such things do not change. Society can't develop innate feelings. They are either innate or need to be developed.
Why should I care what feelings society developed? Society is flawed. What if society developed a feeling that killing is pleasurable and moral. Should I need to change my views to accept those of society? Society is not the be all and end all- only G-d is.
Back up one second. So now murder isn't immoral? Do you see the pretzel you're twisting yourself into to try to convince yourself that morality requires religion.
I haven't twisted myself at. Murder is by it's own nature neither moral or immoral. In those cases that G-d decreed it immoral it is immoral and in those situations that G-d demands it, it is moral.
But you haven't answered my question:
If G-d would have created a Torah where it was a Mitzvah to kill innocent people- would you? Would you consider yourself immoral?