%establishmentarian%

n. The doctrine or political position that advocates abrogating the establishment of a church as the official state religion.. [ PJC ]

Prior to the Puritans, very few earlier believers contended for any form of disestablishmentarianism. David. W. Hall (Savior or Servant? Putting Government in Its Place: The Covenant Foundation, 1996)

n. One who regards the Church primarily as an establishment formed by the State, and overlooks its intrinsic spiritual character. Shipley. [ 1913 Webster ]