Christians were originally called atheists by the Romans!
Christians were routinely punished by the Romans who saw their religion as impious and backward. Beginning with Jesus, Christians were rounded up and executed for their religion over the course of three centuries. The Romans characterized them as “impious atheists” because they did not believe in many gods. Virtually everyone in the ancient world agreed there were many gods, which is why Christianity and Judaism were considered so bizarre.
In fact, the act of praising only one God was so foreign to the Romans that they considered it equivalent to denying the existence of all gods and thus labeled them atheists!