Fitting the concept of god into a cosmological model is rather easy.
If we agree that everything we see is described by physics, then everything including us is simply a computation. And in principle someone can build a machine to carry out such a computation.
People in such a machine will be more or less like us, and the creator of that machine will be exactly like god, outside of space and time, omnipotent, omniscient but having to run the simulation to see what everyone does.
From this point of view creating universe 6000 years ago and making it look billions of years old does not look that insane, just a workaround for finite machine time.
So the main disagreement is not about existence of god, or materialism vs idealism, but whether a human is equivalent to a computation or not.
Alternately, an individual set things in motion that they couldn’t control or stop, and thus the universe was born. God could just be a random entity that got in over their proverbial head. We think creating a universe requires thought or intention but it could be a big mistake.
The main idea of what I am saying is that some entity could have kicked things off, for whatever reason, and not be able to stop or control it. Perhaps they were just like you or I, and they released some tech which formed the universe as we know it today. Perhaps they are outside of this universe and cannot see into it or control it, perhaps they were inside and were obliterated, perhaps they are still here somewhere sitting around waiting for the universe to end, who knows! Everyone expects a god to be all-powerful or something, but they could be some mortal being who only had a lot of power for a moment when they knocked over the first domino. We probably can't know how the universe started, in any case, so this is all just brainstorming for new sci-fi and fantasy novels at this point.
If we agree that everything we see is described by physics, then everything including us is simply a computation. And in principle someone can build a machine to carry out such a computation.
People in such a machine will be more or less like us, and the creator of that machine will be exactly like god, outside of space and time, omnipotent, omniscient but having to run the simulation to see what everyone does.
From this point of view creating universe 6000 years ago and making it look billions of years old does not look that insane, just a workaround for finite machine time.
So the main disagreement is not about existence of god, or materialism vs idealism, but whether a human is equivalent to a computation or not.