Sabellianism, a heresy about the distinction of Persons in God, the name of which is due to Sabellius, of whom but little is known, save that he was most probably a native of Libya, came to Rome under Zephyrinus, and was banished by Callistus, whereupon he took refuge in the Libyan Pentapolis. The Adoptianists and Modalists up to this time were the chief divisions of the Monarchians, the former making Christ the chosen of God, His divinity the effect of a complete oneness of will with Him, the latter making Him merely a manifestation of God. Modalism prevailed in Rome under the patronage of Calixtus, but was denounced by Hippolytus, who was himself accused of ditheism. Sabellius led the more extreme Modalists, and offered strong opposition to Calixtus, but his influence was far more important in the East than in the West, where the phrase of Athanasius that the Son and the Father are one and the same in substance (ὁμοούσιος) was at once accepted, though rejected at Antioch in 268.
The earlier form of Sabellianism was almost identical with Patripassianism, the chief teachers of which were Praxeas, Noetus, Epigonus, and Cleomenes. But it developed into a complete resolution of the Trinity into a mere threefold manifestation of God to man. Father, Son, and Holy Spirit are not distinct subsistences (hypostases), but merely one and the same person in different aspects, just as the sun is at once a spherical body, a fountain of light, and a source of heat. The single absolute Divine Essence—the monas or pure Deity—unfolds itself in creation and the history of man as a Trinity. The energy by which God called into being and sustains the universe is the Logos, after whose image men were created; but when they had fallen from perfection it became necessary for the Logos, or Divine Energy, to hypostatise itself in a human body, in order to raise and redeem them; hence in the man Christ Jesus dwelt the fullness of the Godhead bodily; while the same Divine Energy, operating spiritually and impersonally in the hearts of believers, is the Holy Ghost. Sabellius held further that these Divine manifestations are merely temporary, and that after the Logos and the Holy Ghost had done their work they would be reabsorbed in the absolute Deity—the trias would again resolve itself into the monas; or, in the language of St Paul, that 'God would be all in all.' Epiphanius alleges that Sabellius derived his system from an apocryphal Gospel to the Egyptians; and there are, as Neander points out, so many points of resemblance in Sabellianism to the Alexandrian Jewish theology in general that the statement may be regarded as at least indicating the direction from which proceeded the influences that determined the theosophy of the unknown Pentapoltan. The 4th-century heresy associated with the name of Marcellus of Ancyra was closely allied to Sabellianism, which indeed becomes a term employed somewhat loosely. The followers of Sabellius were formally suppressed by the Catholic Church in the 4th century; but his doctrine, which, divested of its Gnostic and Neoplatonic phraseology about emanation and re-absorption, &c., is substantially Unitarian, has seldom wanted eminent advocates in any subsequent age of Christianity.
See the Church History of Neander; discussions by Schleiermacher and Lange; Döllinger's Hippolytus u. Kallistus (1853; Eng. trans. by Plummer, 1876); and Zahn's Marcell. v. Ancyra (1867).