I’ve had a number of conversations with theists in which they tell me their beliefs are grounded in evidence, not blind faith. As a scientist, I’m surprised when they can’t offer a hypothetical scenario in which they would change their beliefs. Because that’s the thing about basing your belief on evidence, isn’t it? If you get different evidence in the future, or you develop a new model which explains all your evidence better, you change what you think is the most likely explanation.
Part of the reason this happens, I think, is that these theists don’t have specific, clear ideas about the gods they believe in. Once you nail down a claim, it becomes possible to collect evidence showing that claim to be false.
Does your god always answer believers’ prayers? Does he answer the majority of believers’ prayers? We could actually do studies to test these things (and we have). Perhaps it would be safer to claim that one’s god might answer “yes”, “no”, or “wait” — rendering his answers indistinguishable from no answer at all.
Does your god protect the health and well-being of believers? Does he help and heal believers when they’re going through times of hardship or illness? Does he give believers hardship and illness to test or strengthen them? Does he sometimes kill believers (or, allow them to die) because he wants them to join him in the afterlife? Or does he do a mix of these things, making his interventions conveniently appear identical to chance events drawn from probability distributions we can calculate based on terrestrial, natural phenomena?
I know some theists think they are presenting a clear statement about their god’s nature when they say he “works in mysterious ways.” I wish these folks would just admit that their beliefs are based on blind faith rather than pretend their claims are legitimately evidence-based and testable.