If morality is subjective...

[Mister Agenda]

Then how do we answer the theist argument - If there are no objective or absolute moral standards then every individual's moral spectrum is equally valid, and therefore practices, actions and habits like murder, sex assault, violence, mutilation, torture...[the list goes on] should be perfectly acceptable and not censored in human societies.

[I'm sorry if the answer is obvious but I don't know how to refute this one]

I don't see how relativism prevents one from saying than one thing is more or less moral, compared to another. Relativism can't reasonably be defined as 'all moral practices and principles are equivalent'.