What if using evidence to try to find out of there is a God is like using a metal detector to try to discover a heavy metal band? It is based on a misunderstanding of how reality works.
Then we could never be justified in believing there is a God. Because I know of no method to tell the difference between things which don't exist and things for which there is no evidence. If we can't find out about something with evidence then what can we find out about it with?
Imagine for a moment that I propose the existence of a square circle. And when you point out such a thing is not possible I say "Well you're being arrogant because you haven't ruled out that it could exists outside of all geometric planes. How do you know in the future we won't have the necessary mathematics to describe a square circle?"
I think you would find such postulations tedious and blatantly ad hoc. The very notion that I'm having to go outside of geometry to make my square circle work is a huge red flag I don't have good reasons for believing such a thing exists.
The same is true of the God hypothesis. If we have to redefine what existence means or postulate evidence is the wrong tool for the job - then that should be a red flag we are not on a path to knowledge.
Philosophy is a great tool for making sure we're using the right epistemological methods and asking the right questions - but untempered by real world data it can only explore the theoretical. Never the actual. And arm chair speculations and ontological arguments are never going to get us to a justified belief in God(s).
Most importantly, it's not my fault if believers can't find a way to verify or falsify their beliefs. It's not my fault they can't think of a set of evidence that would prove the existence of the creator they claim exists. Because it's the person making the claims responsibility to provide evidence - not my responsibility to design tests for them. Onus Probandi: burden of proof / burden of persuasion falls to the person making the claim.
For example, I don't believe in the Multiverse. And simply saying "Well scientist don't have a way to test the theory therefore we are justified in believing it." - is NOT a valid argument. If someone claims the Multiverse is real it is up to THEM to provide the evidence. And if the hypothesis is unverifiable and or unfalsifiable then their belief is unwarranted.