Reality Versus Simulation

I am not advocating that you and I are simulations. Neither are any group of physicists, at least in the mainstream of physics (not that I know any personally or am trained or practice in the field). We are not imaginary simulations of God, figments of God's fanciful imagination.

However, I do like to play around with different wonder-if scenarios.Why can't we play around with our imaginations and explore different situations and imagine what it would be like? Why leave the speculative fun to others? So, a wonder-if question I have is: what if we were simulations and are unaware of it?

A related question is what is the true nature of reality? Leaving the question aside of whether we have non-physical spirits that are not governed by the known laws of physics, there is a lot about our appearance and the world around us that is misleading. Over the last few hundred years our understanding of our composition, what we are made of, has changed considerably. We discovered that we are made of up of thousands of billions of individual units of life called cells. The cells are made up of a lot of structures, such as membranes, proteins, and long curled strands that encode our genetics. These are composed of atoms -- which in turn are composed of smaller particles and forces. If we were to see the actual particles themselves at the smallest level and see how much space it all takes up -- we'd discover the vast majority of the volume of space we occupy is nothing! We we look at the person sitting next to us, or a rock, or a mountain -- we are seeing the result of light and the electromagnetic force giving the appearance of solidity. But in reality, over 99.9999 percent of us is made up of nothing.

So, what if God made a simulation of our world, the universe, and us based on ephemeral mathematical formulas or patterns? How much different would we be in the simulation from us in the real world? Already we see that us in the real world is made up of the vast majority of nothing. How much worse would a simulation be? And if the simulation was really good, would it matter? When does a simulation stop being a simulation and cross into reality? What is absolutely crucial in our reality that is not captured in a simulation? And if that or those crucial elements about reality can be identified, would it be possible for God to simulate those to perfect fidelity? And if it were possible, what is the difference between the simulation and reality that is important?