It would make do difference to me at all. If there actually was a supreme being, it couldn't possibly bear any resemblance to the judeo-christian spoiled brat child god. Even if it was aware of me as an individual (highly doubtful) I'm sure it would have zero interest in my fleeting existence. What's the point of worshipping and praying? You might as well talk to the the big bang for all the good such a thing would do.
I would engage in a logical debate with God about why he did so many cruel and evil things? And why would he create homosexuals? And about why did he keep evolution and dinosaurs out of the bible because we'd both know that they exist?
This is probably going to sound like a funny answer, but I would continue living my life as I do without him. The problem is that the Bible is filled with contradictions, including that Hell was never described as a fiery place where people burned-- it was originally a cold, dark state of being you found yourself in when you were away from God. I've always interpreted heaven and hell to exist while living, not after death. I also believe that if an intelligent, human-like god existed (and he is human like in the Bible-- anger, jealousy, and other such emotions are human in nature), then he would appreciate people who logically challenged his existence and would be more concerned with people who were living virtuously than people who happened to pick the correct religious denomination out of the like, 40,000 that exist. I can't say I believe God would be bothered by my Atheism at all (especially considering the going rates for Christians in prisons in America--- over 95% of them read the Bible and identify with religion and only .2% are Atheist) because I haven't ever done anything harmful to anyone or anything and I live honestly. If he wanted to beam me to hell anyway, he'd be welcome to--- I wouldn't want anything to do with a god that didn't have a sense of humor.