What is Atheism?

[Neo-Scholastic]

If homeopathy was believed in for centuries and almost everyone but a few irrationally skeptical scientists believed in it unquestioningly, to prove it really works, the null hypothesis to overcome would still be 'homeopathically treated water is indistinguishable from the same water if not homeopathically treated in its medical effects'.

I guess what you are trying to say is that a world without God is indistinguishable from a world in which God exists. Is it? That begs the question by assuming you already know what a godless universe would look like.

In the homeopathy example you have the ability to isolate variables by comparing treated and untreated water. How does one create a sample set of all existence in which God exists to compare with a control set of all existence without God? It cannot be done and it is ludicrous to suggest an impossible test be used to test the proposition.

'The world is all that exists' is the null hypothesis. If you want to show that something besides the world exists, that's the proposition that you need to overcome.

If you are going to take that to the ultimate extreme then the null hypothesis is actually solipsism. Anything else, including 'The [physical] world is all that exists' is an alternative explanation or profoundly incurious. (I added 'physical' to the proposition to clarify my original meaning.)