How can souls be the real thing?

If you look at historical records, the concept of a soul has existed long before it was ever "revealed" by any ancient prophet, with tribes and ancient civilizations already coming up with an ethereal substance that connects them together as a species, probably to feel important with respect to animals or to create a connection with their pre-existing deities. In fact, the Jews formally recorded the idea of the soul in their religious texts based on traditional beliefs which had not come from divine inspiration. So, if souls as described in the Bible and prophetic texts are a human invention derived from reason and other social beliefs, then how could this possibly coincide with what is actually true? The "system" for our connection with God and the supernatural world could literally be anything outside our wildest imaginations, and it just so happens that it's exactly the same as how humans had originally believed it to be? Do souls really exist? But then, if souls don't exist, can heaven or hell even exist either? In fact, those have also existed as concepts since ancient times, and it's clear how their creation by a society could positively benefit it (e.g. an elder telling kids they will suffer eternally if they disobey, lie, steal, etc. and this evolving into widespread belief)... Without these principles, everything about Christianity falls apart, so where does the reasoning go wrong? Sorry if this seems a bit anti-religious, but they're genuine doubts of mine.