Cofty I think it’s pretty clear that the God you don’t believe in doesn’t exist. We can agree on that.
It’s the ultimate God of the universe I think most are interested in,
You have a classic “yeti or Loch Ness monster theory of God” approach to the question, as described by Terry Eagleton. This is the idea that the existence of God can be approached the same way as the existence of a mythical creature can be proved on the basis of empirical evidence on a case by case basis. This theory doesn’t take into account that many believers do not conceive of God as a “thing” that can be evaluated in this manner. Indeed the approach assumes what it is supposed to prove: that if God exists he should conform to a reductive materialist conception of reality. And since no God can survive in this reductive materialist environment (as Loch Ness cannot sustain a monster or family of monsters) God is implicitly ruled out. But this process proves nothing other than the person’s prior commitment to a reductively material universe.
The problem with eliminating the gods one by one in the simplistic fashion that Dawkins and other atheists recommend, is that it apparently takes no account of the possibility that there may be a God with some basic features common to many faith traditions, but identical to none. Or to put it another way, it doesn’t allow for the possibility that existence is a common feature that religions have correct about God, but that the actual characteristics of God may not be fully apprehended by anyone.
If there is a God then it does not seem unreasonable to suppose that he may exist in a fashion which is not identical to any particular human conception of him. Or indeed in a way that is close to some or one tradition, but differs in some important respect. All of these options seem logically feasible, and entirely untouched by a simplistic process of eliminating human conceptions of God one by one.
All you are doing in this process is eliminating gods you don’t believe in. It is not touching the ultimate question of whether there is a God at all.