We’re not talking about laws and enforcement, you just agreed with me that murder is the unlawful killing of someone, and that no society has tolerated it because they draft laws around it.

People with no moral basis in religion conclude that morality is subjective. Which is wrong, it is very objective. No society or people past or present has ever tolerated a thief for example. No society has ever tolerated a murderer. There are things, more than the two examples I give, that are wrong universally whether people in this day tolerate them or not. And some people past and present tolerate other evils. That doesn’t change what they are.