Theists often ask, “What would it take to change your mind about the existence of God?”
That’s easy. It’s really no different from what it would take to get me to accept any other questionable assertion:
First, you’d have to give coherent definitions of “God” and “exists,” with enough informative content that testable predictions could be made from the assertion “God exists.”
Second, you’d have to infer some such predictions and rigorously test them in an attempt to falsify them.
Third, you’d have to fail to thereby falsify them, instead getting results from those tests for which “God exists” has fewer and smaller assumptions, better corroboration, and broader explanatory power than the available alternative hypotheses for those results.
If someone does this, I will happily credit that “God exists” fits the available data better than any known alternative hypothesis, and I will tentatively hold “God exists” as something I know.
If the assertion “God exists” is true, it shouldn’t be that hard. People do this kind of thing every day, in all variety of fields.
How about you? What would it take to change your mind?