Belief in God requires faith, not proof. By demanding proof the atheist is being unreasonable.
Further the atheist is being inconsistent because there are many, many things we believe, which we don’t have empirical evidence for, and which can’t be proven. Faith, belief in the absense of complete proof is required for everything.
Now faith in God is reasonable, like faith in the past is reasonable. There are many lines of argument which indicate God exists, even if they don’t prove it. Just like there are many lines of evidence indicating the past exists, even if they don’t prove it.
I currently think the problem is there are important differences between how God is unproven, and how the past is unproven.