The lack of evidence for something to exist is not inherently a problem. Take for example black holes, they were only theorized before discovery.

You don’t need to prove something doesn’t exist, it’s just a moot point. For any skeptic, as a matter of epistemology, not having any proof is as redundant as having proof for its nonexistence.

The lesson religious people need to learn, is as aforementioned; not having proof should be the disqualifying factor, not proof to contradict their established beliefs