The root issue is - I am this body. As long as that idea is there, the spiritual search is an endless vicious circle.
The body is taken to be a thing among things - a small thing which came into being and will end. From that idea the search goes on - trying to understand the wholeness of reality from a broken, separate perspective. A thing is trying to become the whole. It is an impossibility. AS a thing, you will never find what you are searching for. AS a thing you will forever be stuck in only an intellectual understanding. Paradox.
As long as this idea you have about yourself remains, no end is in sight. A separate thing cannot find the reality of nonduality or wholeness. You cannot intellectualize it away. A thing cannot become the whole.
So all efforts should be directed at the investigation of the reality of the body-in-the-world idea. The person. Investigate it by any means possible. Look at it without pre-conceived notions, like it was the first time you ever saw it, and didn't yet have any names for it, any memory of it, any ideas about it.
Investigate the idea of the senses. Investigate how the brain actually works. Look as if a scientist trying to investigate some new discovery, something which is there but you don't know what it is.
It is only the persistent assumptions which seem to cover reality.
How do you know the person or the body? You know only of experience. Raw experience which has not yet been given a name. It has not yet solidified into a thing. You know of changing experience to which you apply memory, assumption and belief. Otherwise body is only mystery - you don't truly know what it is without this mechanism. And there is fear to let loose of the assumptions/beliefs. Because the mind cannot deal with mystery - it has to come to a solid concept about things. It is left feeling uncomfortable and unstable when it cannot fit everything into nicely wrapped packages.
Let that mystery come. Truly taking an honest and unqualified look at what we know, we recognize that we really don't know what the Hell it is. We realize that our entire life, the reality and identification with body and thoughts is truly only ever assumption. It is like a splinter in the mind - it is unsettling - to the mind it is a source of fear and uncertainty. Don't fight the splinter. Let it stick. Let it act. Let it fester and infect.
At some point the bottom falls out of the bucket - it is realized that there is nothing at all of our life story which can be said to be absolutely true. It has always been a story, a tale told to cover the inherent mystery. In that story there is a diminishing of the fear but along with that comes this insistent impulse to discover the truth about what we are.
But we cannot discover what we are without facing that mystery, without letting that mystery be as it is without the immediate scramble to fill in the blanks with concepts and imagination.
Until then, you, as a body, are stuck. ARE you truly a body in a world? Have a close look. Face the mystery head-on. Don't be afraid. The snake in the room is truly only a rope.