“May an on-campus sorority limit its membership to women and a fraternity to men? We have easily answered that question with a yes. We have also easily answered the question of whether a synagogue may only hire a Jew as its rabbi or an Episcopal church only an Episcopalian as its priest. But may laws forbidding discrimination based on religion prevent a faith-based organization that is not a religious congregation from limiting its members, leaders, or staff to persons in agreement with its religious beliefs? Differences of opinion, and at times bitter controversy, have arisen.” Keeping the faith on campus