Hi Flower Girl,
The beauty of Newtonian physics is that is it perfect, irrefutably able to predict precisely--even to the microscopically level--what will happen.
Depends what you mean by “microscopically”, but Newtonian physics (or mechanics) while incredibly useful for most day-to-day purposes becomes more approximate at the quantum level.
But, quantum physics challenges Newtonian physics as the final reality, that we've always truly "known" the physical world in which we live.
At a deeper, more precise level perhaps but we cannot say “final” because we can’t know whether there are underlying strata of reality yet to be discovered.
I'm just suggesting that looking for "proof" of God's existence is challenged by our own physical understanding of just exactly what "proof" is.
First, “proof” is freighted with meaning that’s superfluous here. Mathematicians and logicians use it, but science doesn’t. Rather it looks to reason and evidence that indicates provisional
ly the truth of a proposition. That’s why in science theories are in principle falsifiable.
Second though, what you’re attempting here is a fallacy in reasoning called shifting the burden of proof. If someone wants to argue for “god” (and if they can actually come up with a coherent meaning for that term) then the burden is with them to show that’s it’s more probably true than not. You cannot in other words assume god
a priori, and then argue that the problem with demonstrating the claim lies with “our own physical understanding of just exactly what "proof" is”. If you think there’s a god and you want the claim to be taken seriously, then it’s your job to tell us how the claim can be investigated and justified.