You have heard the questions. When a theist learns you are atheist, they invariably show surprise and start asking questions. “Surely you must believe in something?” they ask with worry. “Do you believe in Satan?” some will ask with a sense of terror.
For many theists, a belief in a god is natural. For the atheist, it is not natural to believe in a god. There is not an atheist belief system that says people must reject all of the gods man has invented. Yet, for many theists, it is so natural to believe in a god that they question how a person can live without such beliefs.