I study weekly with someone that observes Mitzvot and believes that the bible was given to the Jewish People by God. Recently he said something that I found surprising, and I wanted to try to understand if his statement was part of the beliefs of many in mainstream Orthodox Judaism. What he said was that even if he someone discovered that God did not exist, he would continue to observe the Mitzvot to the best of his ability. I have always understood that the Orthodox Jewish perspective has at its basis that God gave the written/oral laws to Moses, and they are passed down through the generations. If God is removed from this equation, it seems to me logical that the entire basis for the Orthodox Jewish belief system would be in jeopardy. Yet my study partner did not agree with this. I would be interested in hearing your perspective.

I feel these are "What If" Questions that are useless to ask. Since we know G-d does exist and had created the world and no one can ever prove otherwise, these are hypothetical useless questions. Maybe what he meant was that he will never accept such "proof" since he knows better and the proof must be false.