Isn't amazing that so much of Western religion depends on a single assumption: the existence of a soul or spirit.
Now, what do I mean by a soul? From an Abrahamic point of view, the soul is that immaterial entity that is supposed to be 'sitting' behind our eyes, driving our actions. This spirit interacts with our bodies and minds, and most remarkably, existed before birth and survives our death.
With these traits, the spirit must be physical in some manner and in principle, measurable. At what level does the soul interact with the brain? Does it interact at the sodium ion level in the neurons that are part of the neural signal process? Does it interact at the cell level? Or is it at the whole brain level? What is the mechanism? Or is the soul just the mind? The complex patterns of neurochemical signals make up the mind and in some sense, the mind is like computer software. If that's the case, the mechanisms of interaction can be found and are the subject of active neuroscience research.
But that mind depends on the physical properties of the brain. And without that brain, the mind has no place to run (at least until technology makes that possible). How can that survive death without some 'upload' process? And since that mind is information, a complex pattern, that depends on physical processes, how can that pattern exist without some physical container? Any entity that is not material, that is not measurable in any way, does not exist in our physical reality, and is in fact, immaterial.
So, does the soul exist? I think yes, if all that is meant is the mind; a mind that develops and grows through life, but disappears and disintegrates upon death. But if the soul is some ethereal entity that has no physical form or is not measurable, then I don't think that such a soul exists. And without an eternal soul, what meaning does religious salvation have? The threat of hell or the promise of paradise, which many contend are the hallmarks of Western Abrahamic religion, ends up being meaningless.