A denomination can be distinguished from a sect, in that it co-exists with other religious bodies and does not define the world outside the group as evil or at least highly suspect. A denomination is also distinguished from a church in the academic study of religion, in that the latter is a state-sponsored religion. The term "church", used this way, is confusing to many in the USA, since this country does not have an established church. Recommended reading: Ernst Troeltsch's works.