a rough approximation of God’s Law with regard to the family works, never mind the specifics.
Plants and animals are subject to evolution, undergoing mutation, replication, and selective pressures from their environments, including other plants and animals. This has been observed in at least one species (of lizard, I believe) within human lifespans, nevermind the bacteria.
Why would ideas be any different?
You believe that this similarity emerges because of divine decree, but there is another path.
Ideas emerge naturally from interactions with the environment. Creativity involves creating new links between existing concepts. Plus, people just think about stuff. This is the source of ideas mutating and new ideas entering.
Ideas, then, will traffic on a combination of their appeal and their linkage with reality, with appeal higher in pressure when the effects are far more distant. This forms the basis for the selective pressure.
Any religion that spreads to be widely believed, then, is going to contain a number of concepts that are effective. If it were too ineffective, it would be destroyed, either by destroying those who hold to it or by being abandoned. If your plan for making a canoe involves drilling a big hole in the bottom, it isn’t going to propagate.
Some of these concepts can be things like, in environments without antibiotics and genetic paternity tests, monogamous marriage and banning adultery.
But of course, that isn’t a guarantee that all these practices will be good. Multigenerational cousin marriage is a tradition in the middle east, where it is successful at some goals (keeping wealth within the family), and damaging over the longer term to health and wellness.
So, of course, the alternative reason that these patterns, which have some success and similar to ones in your religion, keep coming up, is that your religion itself was evolved to obtain them in much the same way.
It’s worth noting that in @argumate‘s recent chain of posts, one user brought up that the Catholic church had stricter standards for heresy, because the common people were more eager to accuse others of witchcraft and the like. These impulses and status warring, then, can explain some of the other effects, including those of the Left eating itself.

