Man seeks to know. God is a theory, offered to explain the unknown.
As the iron fist of Chruch rule over truth was broken by the dawn of science, and as Religious Authority was revealed to have been wrong about some things, other competing theories were free to be offered. Darwin, for example, no longer had to fear being burned at the stake as a heretic. Religious Authority was relegated increasingly to a smaller and smaller domain of only those things that could not be proven and could only be taken on faith.
But all of these theories, such as God or Darwinism or the Big Bang, tend to share the same lack of testability. They may all be sophistry, nonesense masquerading as sophisticated thought. Good explanations have testability as a property. Even Einstein’s claims about all instances of certain phenomena across the entire universe, past, present and future, even much of those highly regarded claims, cannot be verified or falsified.
If something can’t be tested against experience, then is it really justifiable as part of a strong theory?
It seems to me, for example, that this is one reason why Academics have such a firm strangle hold on published Philosophy. Absent testibility or falsification, then the credentials of the claimant take on a whole new use. Instead of offering proof, I offer my credentials. (Personally, I would be in favor of this predjudice, if only being wrong carried a more severe penalty. For example, any Economist could sell the government on any new economic theory, but if it did not work, then off with their heads. One would have to have the courage of their convictions, so to speak.)
Science develops theories, verifies or falsifies them, and thus is scientific progress achieved. Not possible with some theories, including the theory of God, among many others.
But I wonder, why accept some theories that can’t be verified or falsified, and yet reject others? Why accept Einstein or Darwin, but reject God? It seems to me that if one is going to reject what cannot be verified or falsified, then one ought to do so without predjudice.