Modern ecclesiology is too concerned with the ideal church, and pays too little attention to its sinful everyday life. Pluralism and postmodernism are discussed, and the argument made that well-meaning attempts to affirm non-Christian religions make it difficult for them or the church to argue that its convictions are true. The book shows that one can talk about the church and other religious communities in ways that acknowledge their uniqueness and truth claims, but also their problems and mistakes. New disciplines are proposed: theological history, theological sociology and ecclesiological ethnography.