What's your theory about the Universe?

I believe that "God" created our universe that erupted from a singularity in a "Big Bang." The universe is still expanding but the expansion appears to be slowing from what I have read.

There is no consensus as to whether expansion will continue until entropy has been fully achieved, or all of the matter in our universe will contract once again until it achieves singularity.

I also believe that there are many, perhaps an infinite or near infinite number of universes, each with its own laws of physics and physical constants. There may even be "parallel universes," that have at one point in time or another "branched" away from our reality.

As to what is outside our universe, or all universes, I simply don't have a clue. Is it nothing, the lack of everything and anything? Or is it some environment of its own, perhaps a super-universe that contains innumerable universes within it? If that is the case, are there Super super-universes?

Looking at the structure of matter in our universes, we have yet to find for certain the smallest, most foundational unit of matter, e.g., everything in our world is made up of molecules that have bound together atoms, which are comprised of neutrons, protons, and electrons, which are comprised on smaller particles and so on; just as stars, planets, comets, and other matter bind together into solar systems, which bind together into galaxies, which bind together into clusters, which bind into super-clusters.

There appears to be great symmetry in all things we can see, big and small.