God is just as relevant. Because even the scientific mechanism that one postulates is simply degree of explanation that is satisfactory. There is no reason to believe that the ultimate explanation can be scientific and in fact, considering certain elements of Scientific methodology cannot be explained by Science, the ultimate explanation definitely cannot be a Scientific explanation.
First it hasn’t been established what “ultimate explanation” means, let alone how we would identify such. For any given putatively ultimate explanation, we can just “Quine it”, and wonder why that “ultimate” circumstance is the way it is. Knowledge is never ultimate, or it’s not knowledge. That’s not news to science, and is in fact a significant ramification of employing the scientific method to build knowledge. This is apparently unknown in some religious circles (yours!), and is a form of superstition all on its own, untethered and unwarranted, that there is some “ultimate answer” that is in any sense ultimate or an answer, at all.
There is nothing but superstition supporting that view. Science disavows that epistemologically, and understands that the frontiers of knowledge necessarily must trail off into ignorance and non-knowledge somewhere. It doesn’t even recognize that what you are chasing is chaseable, let alone actual and catchable.
Or, as a philosophy professor once asked the class: OK, you are God, or god-like, you think. Do you know everything? Do you have ultimate, infinite knowledge? How do you know? How would you test that proposition?
I understand your position will be “it’s self-evident!”. But think about that a bit more, please.
Then there’s the problem of default. For whatever limitations you and I can agree on for scientific and empirically grounded knowledge (and these are not controversial I think), such limitations IN NO WAY concede “the truth” or assign authority to superstition or intuition. If science stops making headway at this particular point, or that, why would you suppose your superstitions are going to succeed where science has run out of gas. There’s a glaring non-sequitur here: at the point where science gives up, my superstitions take over as authoritative and become “true by default”. But your superstitions never did anything to establish any epistemic bona fides on anything. They couldn’t even acquit themselves on the easy stuff, the questions that science was able to take on. Why on earth would you suppose that when science fails, magical thinking would become authoritative?
Now however, this is NOT why Christians believe in the existence of God. Existence of God is through deductive reasoning based on self-evident truths.
Right, and here the trap-door of “self-evidence” snaps open wide. Should I just say “the non-existence of God is self-evident”? That’s nonsense, or actually not completely nonsense, since God is “unseen” (even per the Bible) and manifestly not self-evident, but even so, it’s a bogus claim for me to advance. But I’ve as much warrant to advance that as you or Aquinas does for the “truths” you and he hope to excuse through the loophole of “self-evidence”.
Btw, you might have missed my post right before
(Post 67) where I refute your original argument. Did you miss it or are you agreeing that it was wrong?
God Bless

Must have missed it. Looking back, I think you must mean post 67. You made it clear you weren’t interested in more of the same from me on that, and that’s immediately what you’d get right back, as it was same song, same verse on your end. I’m happy to respond, but it seems a waste of time, if we’re stuck in the rut that you yourself identify.
-TS