There is a scene in one of Ian Rankin's marvelous Inspector Rebus detective novels at which a young English police-woman, freshly posted to Rebus's Edinburgh, errs in her choice of soccer team. She gets a short tutorial on the importance of religion in the contemporary world. There are different teams, she's told, "'wherever you've got Catholics and Protestants in the same place.' Manchester had United (Catholics) and City (Protestant), Liverpool had Liverpool (Catholic) and Everton (Protestant). It only got complicated in London. London even had Jewish teams."