QUESTION: If there is no God, then why does every society have a religion?
AN ATHEIST’S actual answer: Societies are people. People develop theories and create concepts. The existence of religion merely proves the existence of people. The various concepts of god(s) and the great number of different religions no more provide evidence for the existence of multiple gods than they do so for even one.
A CHRISTIAN (me) answer: This answer is pretty much accurate. The debate on God’s existence must have a different starting place than a society’s religion, or many societies having a religious community. There might be some warrant to asking why the religion exists, but the answer will have to travel further into the depths of the foundation than mere existence of a community idea.