Space does not expand.

Spacetime is about the behavior of Matter; it is not about the behavior of Space.

Would you say that the measure tape was involved with how tall you grew? Of course not.

The measure tape is always right, and yet making the measure tape part of the reason why you grew to be your height is wagging the dog.

In as far as I know, Einstein did not wag the dog, but physicists that accepted his Spacetime theory ended up wagging the dog. They reverted Spacetime. Instead of seeing it as a correct tool, they ended up making Spacetime part of our universe. They created a brain fart.

It is easy to explain. In religion, one has a top-down reality, but in science, one has a bottom-up approach.

That Enlightened approach worked all the way bottom-up until others took Einstein's Spacetime and turned it into a top-down perspective. They are wagging the dog. Never ever should a scientific approach be top-down. It is not science; it is religion. Theories can never be the foundation of science; only evidence can be the foundation of science.