I think that thousands of years ago ancient Palestine was a tiny place almost like an island, and multiple invasions nurtured a special kind of fraternity there. There was a realization that life had balance to it and rules and there were extremes to avoid. In that place there was a realization that all things and all people were connected, not separate; and there was good will for everyone. Much later this culture met with Persia's monotheism and interacted well. It was not long before the two ideas were thought of as the same idea, that God was indeed above all and in all and through all. Its actually not much different from the realization people have today: that there is one Earth, one universe, one sky for all of us to breathe and nothing we do is truly independent from others. Everything we do affects someone else and ourselves. Like then as now, people realize that there need to be rules that everyone follows for the good of all; and some people now just like then see a power in it all and through it all, like a huge intelligence. They wonder (or we wonder) if for example the entire universe isn't smarter than us. While this is conjecture its not terribly far fetched to suppose that people only 5000 years ago were somewhat like us.
Well put.
They were trying top understand the world around them, and were grasping at straws trying to explain it with the mythology they were raised with.
Add to that, were only getting a small fraction of a glimpse from the past as these text only reflect life in the Diaspora after the fact.
In the NT. They were explaining what Jesus meant to them personally, and we have different perspectives to add value. No one community was right or wrong, it was just their view.
As long as we avoid the literal interpretation hanging on ever word we can understand more, as they were not writing that way.
One thing that really advanced my overall knowledge was learning what rhetorical prose was. All of the NT was written in rhetorical prose, its sole purpose was not to write history like we do today. They had and used artistic freedom with the sole purpose of persuading listeners to the core truth in the text. The details were not as important as the core.