Go outside and look above you, what do you see? The sky. What is the sky? The sky is, a desire, a firmament around our planet. This firmament is the seat of divinity, it's the realm of gods and ascended demigods and their chosen followers along with that which enables supernatural abilities but also the place of "heavens" or just random homes/towers that people that lived built for themselves up there and ascended to at some point in their lives. "Up" to us is in actuality "down" to them, because you're close to space/the abyss. From "up there" you can dream/shape more solid things using cosmetic radiation and raw heat/power from the sun which the firmament soaks up which results in evolution taking place and eventually we as a species. In heaven things can be manifest simply and feel just as much like they have substance but light and feathery, the closer you get to the Earth's core the more "rigid" and 'hellish" things become. We find ourselves somewhere in the middle of the two depending on where we physically find ourselves and our spiritual state. The firmament is a closed system in a sense that if you weren't already on the inside you're not getting in here unless via physical means to piggyback on, e.g meteors, ships or whatever. This secures us from outside influence which comes from space itself, space actually having substance and not being an empty space or vacuum.

Now you're probably wondering why when you look up you don't see, think of or feel heavens, gods or whatever, simple really you're supposed to feel, think, and see what's in the "background" or "in-between" the sky, the clouds, the storms and so forth, that which makes up this thing called a sky or simply put the "rest of it".