The premise of moral relativism is logically garbled.

The issue was defending the moral absolutism of monotheism. Thus "relativism" must mean that anything is allowed, but the actual meaning of relativistic is that everything organically exists in its own context.

The logical fallacy of monotheism is that a spiritual absolute would be the essence of sentience, from which we rise, not an ideal of wisdom and judgement, from which we fell.

The fact is that good and bad are not some cosmic duel between the forces of righteousness and evil, but the basic biological binary of beneficial and detrimental. The 1/0 of sentience.

When good is viewed as aspirational rather than elemental, conflicts do tend to become a race to the bottom, as all the evolved complexity, subjectivity and nuance is suspect.

Monotheism is essentially monocultural. One people, one rule, one god. It is tribalistic in origin and function. That individuals are cells in the organic body of the community.

Remember that democracy and republicanism originated in pantheistic cultures, as that was how multiculturalism in a complex reality was conceived. The element as spirit. Plato rationalized the element as the ideal.

The Romans adopted Christianity as the Empire solidified and any reminders of the Republic were buried. Though vestiges of pantheism remained, in the Trinity. Which came from the cycle of Greek year gods. The son as spring, reborn, of the sky father and earth mother. Though the mother was denatured in the interests of patriarchy. Even the concept of regeneration had to be obscured, as the Catholic church declared itself the eternal institution, over the monarchies of Europe.

At least until Martin Luther tried to do what Jesus had tried to do to Judaism, push the reset button.

Any functioning community needs some general sense of right and wrong, in order to function. While asserting it is absolute might reduce debate, but not confusion, as there are no distinctions in the absolute. Consequently anything that serves the establishment is allowed, because the tribal god will absolve any sins.

Consequently it is the monotheists who are the real moral relativists, as good and bad are defined only in terms of what serves the religious institution.