Merely as an aid for imagination, not as a scientific theory, do I propose the image of a universal ether with a gradient. Let us posit that there is another dimension in addition to our three (or foure, counting time). Let us imagine this as vertical, squashing the usual vertical dimension for the sake of this little model. Most people who would stumble on this blog would be familiar with this model anyway, otherwise I could have chosen other words.
The plane we humans inhabit is itself a bit varied in elevation, and I still speak metaphorically here. Some cultures are down in the swamps and some are up on a hill. This may be unpopular to say in certain circles. This does not bode well for those circles, as these differences are glaringly obvious. It is in fact a good way to get familiar with the concept of elevation, since we can see it with the naked eye, so to speak.
Now the universe extends upward from here and downward as well. And it has a gradient. (Which means it is a scalar field, but that sounds too scientific for an aid to imagination, I think.) We could most easily imagine it as becoming increasingly fine-grained upward. This implies various things, such as it being harder, more durable, more solid, more real. We could also say that it becomes more energetic, vibrates with a higher frequency etc, but I am fond of the "fine grain" image. It is easy to grasp and its implications are obvious, if we see each grain as having the same amount of solitidy or content of the real.
Conversely, further down from us reality becomes loose and porous. Digging and shaping there is ridiculously simple - it is in fact hard to avoid even if you try. But creations in these lower shales are less solid, whatever permanence and reality they may have is gifted on them from above, namely from us. To take an earlier example: A daydream is very easy to fashion but collapses quickly when you leave it, and may fade entirely from memory. Many novels are rather close to this level as well, in that they become hard to tell apart from each other and from common daydreams, and fade quickly; but they are easy to get into and so many of them sell surprisingly well.
In the opposite direction, where the ether or "stuff of reality" is more fine-grained, digging with our bare hands is not a trivial task and does not take us very far! Reality soon becomes harder than rock. We are imprisoned under a glassy ceiling of stern, unyielding reality. And that would have been that, if we lived here by accident.
But there are cracks or faultlines in the stuff, which any of us could find if we remain aware. I believe this is what is commonly referred to as grace. And there have been souls in the past with greater power and greater solidity than most men. Whether they are actually avatars descended from a higher realm, or whether they are sages grown from below, this is beyond what I will explore today. What seems certain is that they have lived here, and found places where they broke through into higher worlds. Normally few were able to follow them, until structures were built, which we commonly call religions. Be aware that the religions partly exist in our own world or plane (which is why they are so accessible) and it is possible to be very religious outwardly and yet never poke your head outside the mundane reality.
We could think of religions as giant stairs (or step-pyramids, a kind of monument found on both sides of the Atlantic at different times). They should allow us to ascend to a higher realm and colonize it. From below the step-pyramid seems to grow smaller and smaller and stop completely. But the metaphorical step pyramid which they symbolize are stairs to a vast realm. Because each of the small grains is as real as each of the larger grains below, there is far more room than it looks like up there. Seen from below, those who go there will also become smaller and smaller. Not to worry.
There is to all religions a temptation to spread ever wider into the present world and build ever more elaborate entrance portals, since these are easily seen and appreciated by everyman. The steps could fall into disuse, though I won't give any examples of that. It could happen though, that the Way could get lost.