Another problem with the view that you don’t need God to believe that murder is wrong is that a lot of people haven’t shared your view. And you don’t have to go back very far in history to prove this. In the twentieth century millions of people in Communist societies and under Nazism killed about one hundred million people—and that doesn’t count a single soldier killed in war. So, don’t get too confident about people’s ability to figure out right from wrong without a Higher Authority.
Dennis Prager, The Ten Commandments: Still the Best Moral Code
atheism, right-and-wrong