Imagination. What we don't understand, we must imagine.
We humans don't like not understanding things very much. We're a problem-solving sort of animal. We like to figure things out. However, just on our own, we are limited in what we can understand. Where there are gaps in our understanding, we become uncomfortable. So, we imagine. We're also very good at that. We can imagine almost anything, as long as it's something reasonably close to our real experiences.
So, one of the things we don't understand is the universe we inhabit. We understand dirt, and rain, and the wind blowing on us. We can see them, smell them, feel them and experience them. But, those lights in the sky? They're pretty obviously out of reach, somewhere in the distance. We can't inspect them, really. We can't feel them. We can only see the light of them.
No matter how hard we think about that, on our own we can't understand it. So, that's a problem. We hate not understanding things. But, we can imagine. So, we imagined a being, something like ourselves, that created all of that. We can imagine that, because we create things sometimes. We imagine that being as some sort of all-powerful entity, unlike us, that is able to create such things.
We can imagine what we cannot understand. We imagine a creator that is able, like us, to create stuff. That solves the problem of not being able to understand the universe, at least to a large degree. That way, we don't spend too much time trying to understand what is out of reach. Maybe we'll learn more at some point, but for now, our imagination has filled in the gaps.
Time has passed. We understand more than we once did. Not everything, though, and not everyone understands as much as others do. So, there are still gaps. And we're still filling those gaps with our imaginations. Perhaps there will always be gaps.