Debunking things theists say to atheists

"(Insert famous scientist/philosopher) believed in God, so you should too!"

This argument is an appeal to authority. It suggests that everything smart people believe has to be correct, but also cherry picks. So we should take, for example, Isaac Newton's beliefs in a divine creator over what he discovered and the theories he made?

"You only claim to not believe in God so you can sin all you want!"

This has the same vibes and energy as a young child telling a grown adult this: "You only say Santa isn't real so that you can be naughty all year round!" Atheists also don't believe in sin, so suggesting that they would want to sin is redundant.

"You're going to burn in hell!"

This is once again like a young child telling an adult this: "You're only going to get sacks full of coal from Santa!" Threatening someone with something they do not believe in is hopeless if you want to make them believe it.