I have much respect for Hitchens he was a great polemist, he greatly enhanced the debate community.

A truth is not an untrue just because we lack understanding of it.

The claim that a truth can be disproved without proof is false. Many truths are claimed without proof. For example, if I say there are no purple with yellow polka dot elephants does not mean that I have proof of that. If you say there are no one believes it. The most accurate of all sciences, is the science of math which is based on axioms and theorems. The field of science outside of math has a higher chance of error as we use more of our powers of perception and ability to interpret meanings.

This should not stop our quest for truth. Many philosopher's wrote aphorisms based on truth, without proof they are based on axioms and maxims. Yet there purpose in making these statements was not to end an argument as absolute, but to get the reader thinking critically about whether the statement is true.

Can someone discredit such statement as there is a God without proof yes, but will they be accepted creditably maybe if you are Hitchens. Usually a person of authority can change the communities values, but the bible itself is sought out for its simple truths of proverbs and aphorisms from Jesus Christ. Each person has an individual choice to make what to believe science itself, or logic and reasoning can't solve every problem or choice we have to hope for the best.