The comparison of one’s soul to a flame is common in judaism - so allow me to suggest one more similarity.
People used to wonder why things burned - and why they stopped burning. They had a theory about something called “phlogiston”, which basically is fundamental “fire element” that things must have in order to burn - and when things finished burning, it meant they had run out of phlogiston.
It was only in the 1700s that it began to be debunked, and we now know that fire isn’t a thing, it’s a process. Fire is just oxidation happening really quickly. But back then, they hardly knew about chemical processes. They thought more of concrete causes - like rain and agriculture being determined by gods.
So one can only imagine how they first thought about life - that is, the state of being alive. Especially when death was so common then. They could be talking to someone one day, and suddenly the person’s dead the next day. Their body may look the same, and it looks like they still have all their bones and muscles and organs. But somehow, the body wouldn’t work. They would say, “the soul left it.” It ran out of soul. Much like phlogiston, the soul is thus seen as a fundamental property of the living body. When it’s gone, the person dies. If it can be restored - then perhaps the person could be as well. (Which fits nicely with resurrection ideas of the time.)
But we know today that that’s not what death is. Death is the shutting down of the body’s resources. We know that the body is an incredibly sophisticated machine, and like the best machines and computers out there, eventually parts break down and it simply ceases to work. This is especially true of biological machines (that is, bodies) bc our parts are so fragile. Once we stop pumping blood, cells run out of oxygen and nutrients, they can’t maintain themselves, and so all the cells, each fantastic minature bodies, begin to degrade. After a few minutes, the damage is too far. It’s like a car that’s been totaled in a bad accident - just beyond repair. In a word, entropy. So the body may seem healthy from the outside, but the truth is that it’s already started decaying, even if we can’t see it with the naked eye.
And so death isn’t the loss of a thing, it’s the next step in a natural process - much like fire and oxidation. And so the idea of a “soul” should go the way of the “phlogiston theory” - an imagined substance born out of the naive infancy of our species’ education.
P.s. Another great example of the “inner essence” idea is Aristotelian gravity, which posited that most things fall bc they’re “of the earth”. Feathers fell slowly bc they’re from birds, and so their ‘inner essence’ is a mixture of air and earth. Thankfully we have science and now know that there’s nothing about an inner essence at all. It’s about space-time, about falling in curvature of space itself. Just as fantastic as metaphysical explanations, but without the need for metaphysics.