The good old ‘what if you’re wrong?’ argument.
There is a few ways to counter this irrelevant claim, the first is to turn the argument back on the person giving it. “What if you’re wrong?” can be answered with “What if I’m wrong? What if YOU’RE wrong? What if all this time you’ve been worshiping the wrong God? Don’t you think that if you were the real one would be a bit annoyed?” Pascal’s wager relies on the false dichotomy fallacy, stating that it’s either Atheism or Christianity. But the argument leaves out the fact that there are thousands of other religions that are just as likely to be true. The idea that ‘if an Atheist is right everyone loses, but if the Christian is right then only the Atheist loses’ is pointless; a third statement must be added: ‘if another religion is right then both the Atheist and the Christian lose’.
The second way I have seen people answer this question is to say something like: “I would not want to worship a God who would send me to hell for simply not believing”. Who would want to spend eternity with a God who orders you to worship him otherwise he will punish you forever? Seems just like the thing a maniacal dictator would do.