The parties in this controversy are divided into two general classes: Trinitarians, who hold to a plurality of persons in the unity of the Godhead; and Unitarians, who deny this doctrine. The Trinitarian class embraces what are usually called the orthodox and evangelical churches, such as Baptists, Methodists, Presbyterians, Episcopalians, Reformed Dutch, Lutherans, etc.; while the Unitarians claim about the same number of religious orders as belonging to their ranks. There is, however, this difference in the two classes named: the Trinitarian churches are decidedly of "one faith" in regard to the mode of the Divine existence, and the character of Christ; but with the Unitarians it is far otherwise. Of these there are at least three distinct subdivisions, distinguished by a wide difference of opinion upon the very subject respecting which they are at issue with Trinitarians. They are the Arians, Socinians, and the Sebellians. - Preface.