The journey of life is inward as we travel our own being; we go within our physical being only to expand outward beyond our physical being. The realms, or planes of existence, become more vast the deeper we go. The spiritual plane is more vast than the emotional plane, and the emotional plane is more vast than the mental plane, which is more vast than the physical plane. We look on the outside of our physical being to see what is going on inside, as our behavior on the outside is but a reflection, a projection, of our inner life.
All space is curved, all motion is spiral; we eventually end up where we began; understanding that there truly is no end or beginning. Each successive plane of existence becomes finer, and finer, and more subtle, than the physical plane. All planes are contained on the spiritual plane, which is the largest but cannot be measured, then there is the emotional plane, which is smaller than the spiritual plane, then the mental plane, which is smaller than the emotional plane, and lastly the physical plane, which is the smallest of them all.
They all exist simultaneously occupying the same space at the same time but with different qualities and textures. We can not see these planes with human eyes but we do constantly interact with these planes as human beings; when we think, when we have emotions, we are operating on different planes of existence. We exist simultaneously on all of these planes right now.
It is only a mystery to us as humans because we are exploring and discovering our own being. Actually there are no mysteries; everything is always taking place right inside of us and right in front of us; nothing is hiding from us rather it is us who are hiding; thus the need to wake up to what is and has always been. What we see happening on the outside in this physical world is generated from inside of people on their interior planes of existence and expressed through them into this world.
"Life is like a box of chocolates." Forrest Gump