Some times you feel that "oneness" that the holy ones talk about... you find that place where mind and body, or spirit and body are one. There's no divide, no separation, there's a completeness that is not bounded by thought. It doesn't happen often, but it does happen, so you know that it can happen.
And you think maybe this is what "heaven" is, or eternity, or life after death, or whatever. Maybe it's just a feeling. And the feeling is all.
And then some times you feel like an alien, a rogue presence inside a foreign machine. Yes, it's an organic, flesh and blood, machine, but it works like a machine, and it's part of what you think of as "you" or "I" but it's not the only thing. This is when the mind/spirit feels disconnected from the body. Sometimes this happens when the body decides it has it's own agenda, and that agenda diverges from your thoughts and wishes and plans for the future.
And you think maybe this is what "hell" is, a yawning gap, the place where you are disconnected, and unbound, and spirit and body are a house divided.
So you experience the finiteness of your being through your body, and you experience the infiniteness through your spirit, with an assist from your body. You embody both things, often simultaneously.
And when you die, you change into something else. And we don't know what that is until we experience it for ourselves.
So you have the experience, the knowledge that you are more than your body, but this knowledge doesn't necessarily free you. You can't experience spirit without the body. And experience and feeling is all that matters. So you are caught in that dilemma, that's what we call life.