Sabellianism

In Christian theology, Sabellianism is the belief that there is only one Person ('hypostasis' in the Greek language of the fourth century Arian Controversy) in the Godhead. For example, Hanson defines Sabellianism as the "refusal to acknowledge the distinct existence of the Persons" and "Eustathius was condemned for Sabellianism. His insistence that there is only one distinct reality (hypostasis) in the Godhead, and his confusion about distinguishing Father, Son and Holy Spirit laid him open to such a charge." Condemned as heresy, Sabellianism has been rejected by the majority of Christian churches.

Sabellianism appeared for the first time in the second century in the form of Monarchianism. While "this movement called themselves 'Monarchians', the Greek Fathers called them 'Sabellians', as Sabellius was the person who has put this doctrine in its philosophical form."

Monarchianism opposed the Logos-theology. As from the late second century, non-Jewish Christianity was dominated by Logos-theology which taught a two-stage existence for the Logos: He always existed inside God but became a separate Being – a distinct Reality – when God decided to create. Monarchians claimed "that the theology of the Apologists involves a division in the being and unity of God that is unacceptable" and that Logos-theology teaches two creators and two Gods (bi-theism), "inconsistent with monotheism."

In Monarchianism, "the Father and Son were different expressions of the same being, without any personal distinctions between them. In other words, the Father is himself the Son, and therefore experiences the Son’s human frailties." "In the words of Noetus: …the Father… Himself became His own Son." "It was therefore God who was born from a virgin and who confessed himself to humankind as the Son of God. At the cross, God commended his spirit to himself, as he acted to be dead, but he was not dead in reality, although he raised himself on the 3rd day."

Tertullian was one of the Logos theologians and strongly opposed Monarchianism. "The treatise Against Praxeas is widely recognized as Tertullian's greatest work on the Trinity. The view apparently taught by Praxeas has come to be called 'modalism', thanks to that designation appearing in Adolf von Harnack's History of Dogma (1897). Tertullian simply calls his opponent a 'monarchian'."

"Adolph Von Harnack coined the term 'Modalism' for this 2nd-century doctrine, which referred to the Trinity as consisting of 'three modes or aspects of one divine existence'."

Following Tertullian, "The Latin Fathers... called them 'patripassians' because they have identified the Father and the Son to such an extent that they believed that it was the Father who suffered and died on the cross."

Sabellianism is named after Sabellius (fl. c. 215), who taught a form of it in Rome in the 3rd century. None of his writings have survived, and all that is known about him comes from his opponents.