A rare moment of complete honesty! Sadly, this is what most of us do.
The question of “what evidence would change your mind” is a great one, for a lot of subjects.
For the true agnostic, the answer is “nothing,” for the simple reason that we can so easily be fooled. (Most people use “agnostic” to mean “I don’t know” but I use it to mean what it originally meant, and what it means to philosophers: “There is no possible way to know.”)
So, logically, I’m in the agnostic camp. I do not think there’s any way to know, for sure. But that also puts me in the solipsist camp, since there’s no way to know that there is an objective reality, either. And frankly, well, I’m not a solipsist. So, there should be limits to my agnosticism, too.
If God spoke to me personally and persuasively, I’d buy it. I’d wonder if I were crazy, but unless I had other evidence that I was crazy, I’d probably buy it. I suspect that a lot of religious people are in this camp, except that it’s their heart of hearts that is telling them there is a God, and they don’t feel that God speaks to them directly. I can respect that, as long as they can respect my reasonably strong conviction that their God is fictitious.
If I saw miracles performed routinely and easily attributable to God (e.g., the prayer test mentioned above) I’d question my skepticism.
I got a good dose of challenging my own beliefs some years ago, reading an anthology compiled by J P Moreland against evolution. (I was trying to understand how smart people could disbelieve evolution.) I read the probability argument against the first protein occurring by accident, and the probability was more than astronomical. I was floored. It was gut-wrenching; I felt I had a lot to re-evaluate. If I could have taken an inner picture, it wouldn’t have been pretty.
As it turns out, the argument was flawed, but it was good for me to be challenged that way.