The separation of church and state is necessary partly because if religion is good then the state shouldn't interfere with the religious vision or with the religious prophet. There must be a realm of truth beyond political competence, that's why there must be a separation of churches, but if religion is bad and a bad religion is one that gives an ultimate sanctity to some particular cause. Then religion mustn't interfere with the state - so one of the basic Democratic principles as we know it in America is the separation of church and state.
Reinhold NiebuhrNow the ordinary Protestant, Jew or Secularist has a stereotype about Catholicism. It consists of Spanish Catholicism, Latin-American Catholicism and, let us say, a Catholicism of O'Connor's "Great Hurrah." Now there are types of Catholicism like that but this doesn't - this doesn't do justice to the genuine relation that Catholicism has had to Democratic Society.
Reinhold NiebuhrA church has the right to set its own standards within its community. I don't think it has a right to prohibit birth control or to enforce upon a secular society its conception of divorce and the indissolubility of the marriage tie.
Reinhold Niebuhr