The proposition “God exists” has two words in it which need clarification. The word “god” is confusing to a lot of people as it is full of paradoxes and unclear claims. That is a post for another day. Perhaps less obviously, “exists” is also in desperate need of clarification. That is the focus of this post.
There is more than one type of existence. The one to lead with is almost self-evident existence: the matter and energy that compose the material world. Material existence is basically predictable and very familiar to us. It is self-evident and barely worth a discussion at this point. Our brains are material, and yet they offer us things with are not material: thoughts, emotions, feeling, desires and values. These exist in something I have previously called our ‘internal reality‘. To be consistent, I am going to call this internal reality “internal existence”. To some, I am already being controversial; there are many who believe that as an atheist I should not be able to acknowledge this internal existence. The confusion sprouts from equating atheism with philosophical materialism: accepting only material existence.
The difference between the average materialist and me is a definition question: what does it mean to exist? I have no trouble believing that internal existence is dependent on material existence, a materialist might call that illusory. I’m merely adopting a broader definition of existence.
After this we run into much more abstract ideas of existence: abstract concepts. Numbers, for example. Do they exist? Again, I have made reference to this question before, and the answer is many tiered for there is more than type of number: there are numbers which literally count, this is a finite set of numbers with its limit being the total number of countable particles in the universe (after this number, there is nothing left to count and so no more numbers); there are calculating number, again finite as the biggest number that ever made it into an equation was Graham’s number; there is the infinite, where you can always add one; there is even the Penn and Teller limit to numbers where after the biggest number you can meaningfully picture without grouping (about 4). The short answer is that I think all numbers are conceptual, unambiguous and dependent tools. Numbers do exist so long as they refer to something real. For a number to exist at any given time it must be used as a tool by a mind; the existence of numbers is dependent on a function and a mind to conceive of them. After all, they are concepts. All other numbers–the ones not being used–are part of a huge tool box. The toolbox, containing all possible numbers, can either be thought of as a concept that transcends time or as a concept limited to minds conceiving of them, else as not existing. If the set transcends time, it is because we can conceive of the set being applicable to non-temporal universes.
God does not exist by any of these definitions. We have to invent an entirely new branch of existence to account for God. So far as I can understand from what believers have told me, God is immaterial (does not exist like material things exist), independent (does not exist internally), and exists in Its own right (does not exist as a concept like numbers do).
This is the scale of the improbability of a god. Not only does a god not exist by any understood definition of what it means to exist, so you have to invent an entirely new branch of what it means to exist, but then you have to demonstrate that within that set of existence something worthy of being called a god is what exist there (instead of some transcendent impossible to experience smell). And I imagine you’ll want it to be your God according to your book with your history.
Balls in your court.