I don't think they should call it "church," or meet on Sundays.  It really doesn't matter whether people believe in God or not, but I know that will bother some, who will feel the obsession to prove God's existence.  What really matters is how ethical people are.  The atheists I know are very ethical, while many of the religious ones couldn't care less about their fellow earth inhabitants.  We must remember that the most heinous crimes were committed by people in the name of their deity.

Rather than debate the existence of God, we should be discussing what God really is.  Many think it is a bearded man in a robe walking around on a cloud, controlling people like they are chess pieces.  They fancy this entity as vengeful and angry, and who makes people suffer.  I recommend all read the books "Conversations with God."  Those books will open your eyes in a good way.