Tribe A worships the Sun,
Tribe B worships the Moon,
but the moon tells Tribe B to be hunters & gatherers,
& the sun tells Tribe A to farm.
It is feasible that they could live together in relative peace; until tribe A grows in population wanting to tame the wilderness for farming, destroying the ways of tribe b, or other civic disagreements rend new dichotomy.
Cultural distinctions must definitively be divisive ones; in that there is disagreement as to what is most agreeable respectively. The nature of Human Tribalism would have, presuming no interference of necessity, cultural divisions become geographical divisions ie borders, distinguishing territories. Of course divisions of labor are not necessarily rooted in cultural Religion.