William Lane Craig is very much on form here.

It is a popular Atheist line that you can’t prove the non-existence of a thing. But it is clearly true that you can prove that certain things don’t exist. If you can prove the non-existence of a thing, and you can’t prove the non-existence of God, then you simply have to make less grandiose claims. You have to be an agnostic or something. Dr Craig explains.