The physical human body is controlled by an immaterial soul. To get an idea of what the soul is, go back to the time you had a dream and how real it felt. This is what the soul is. n modern science and psychology we call it the subconscious mind. Otherwise, it's what people call the imagination. Hence, the reason that the body is paralysed during sleep is so that you cannot act out your dreams in the physical reality.

In knowing this, we can understand that anything we do in our day to day, physical life begins in the subconcious mind, imagination, or soul, and then manifests in the physical. You first imagine doing something and then your physical body follows suite. The only reason that you can't see your imagination is because of what occultists call the 'veil of forgetfulness' or the factor that stops you from fully remembering dreams, etc.

Likewise, the soul jacks into the body's CNS and elicits its effects by affecting neurotransmitters and various chemicals in the body. So in essence you are a non-physical entity residing in a physical body.

The soul is the one who feels and experiences life and a fked up soul resultts in various ailments like depression, etc, and this is observed as a neurotransmitter imbalance, but it's spiritual at its core.

So someone can punch you, activate a pain receptor and then your soul experiences pain - likewise you can take a drug like c0caine or m3tth and experience pleasure. This works inversely in that your soul can be tortured and you feel pain or that your soul experiences happiness and your body produces more dopamine.

It is indeed possible to exist in this world and not be of it, by simply rejecting materialism, etc - this way you're not polarising yourself in strange ways and getting depressed when you don't measure up or you lose it all, etc.

I'm explaining this in the most basic and Christian way possible, but admittedly the dharmic faiths explore these concepts to much greater detail. However it is useless to know.