Reply #136: I think Protestantism probably breaks down into 4 or 5 major clusters

[Jackpine Radical]

(speaking as an outsider here). There are the Biblical literalists (evangelical/fundamentalists, Assembly of God, many Baptists, some very conservative Lutherans etc.); the mainline churches (generally not literalists) such as most Lutherans plus the Episcopalians, Methodists, Congregationalists, Church of Christ, Unitarians, etc., the "outliers" like the Jehovah's Witnesses, Amish, Mennonites & others who defy classification; and then there are the Mormons, who are a weird phenomenon unto themselves. The Mainliners range from something near Biblical literalism to the non-doctrinal traditions of the Unitarians and Universalists, and people move from one mainline church to another with little hesitation. The mainline clergy too sometimes move across denominations.

Then of course you get into complications such as the Episcopalians being "sort of" Catholics. I know of one tiny rural Catholic parish that couldn't get the bishop to send them a priest, so they converted wholesale to Episcopalianism and got a priest that way.