Monotheism was the original "groupthink."

Democracy and republicanism evolved in pantheistic cultures, which were the Ancient's version of multiculturalism, as tribal societies evolved into city and nation states. The Ancients were not ignorant of monotheism, but equated it with authoritarianism, as in one god, one ruler. When the West went back to more populist forms of governance, it required a separation of church and state, culture and civics.

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. More the light shining through the film, than the images and story line on it.

This has cast a long shadow, as every ideology that has sought to replace monotheism and its politicial expression, monarchy, was also tended to treat their ideals as absolute. From the Terrors of the French Revolution, to the current cancel culture.

Good and bad are not some cosmic conflict between righteousness and evil, but the basic biological binary of beneficial and detrimental. The 1/0 of sentience.

The problem is that when we treat good as aspirational, rather than elemental, conflicts tend to become a race to the bottom, of us versus them, good versus bad. Rather than each side being able to expect the other will hold to the higher evolved standards of respect, responsibility, trust, honor, love, empathy, etc. and potentially using such situations to further evolve.