Arianism

Arianism is a Christian belief system that challenges the conventional understanding of the Trinity. Its central claim is that Jesus was a creation of God and thus separate from God, not equal to him. The doctrine takes its name from Arius, a third- and fourth-century presbyter in Alexandria, Egypt. Most mainstream Christian churches today consider Arianism a heresy, though a small number of modern groups still hold to it. Some of these groups follow related ideas like Socinianism, and many avoid the label "Arian" due to its long history as a term of condemnation.

Arius taught that Jesus, as the Son of God, was begotten by God the Father before time began. This meant the Son had a starting point—he did not always exist alongside the Father. In Arian thinking, the Son is subordinate to the Father and distinct from him. Arius argued that if the Father gave birth to the Son, then the Son must have had a beginning, implying a time when he did not exist. This directly opposed the Homoousian view, which held that Jesus was of the same essence as the Father and coeternal with him. The First Council of Nicaea in 325 officially condemned Arianism as a heresy, and later ecumenical councils reinforced this stance. Despite this, many Christians at the time had no firm opinions on the Trinity and did not grasp the significance of the dispute.

Arianism also covers several related fourth-century nontrinitarian systems. These included Homoiousianism, which said the Son was of a similar but not identical substance to the Father; Anomoeanism, which asserted total dissimilarity; and semi-Arianism, which viewed the Son as neither fully uncreated nor created in the ordinary sense. The most extreme form of Arianism came from Aëtius of Antioch and his disciple Eunomius of Cyzicus, who taught that the Son was completely unlike the Father.

The controversy over Arianism erupted in the late third century and lasted through most of the fourth. It involved everyone from ordinary believers to bishops, emperors, and imperial family members. Two Roman emperors, Constantius II and Valens, adopted Arian or semi-Arian views. So did many Gothic, Vandal, and Lombard leaders before and after the fall of the Western Roman Empire. The antipopes Felix II and Ursinus were Arians, and Pope Liberius was pressured into signing the Arian Creed of Sirmium in 357. Some early Christian figures, such as Tertullian and Justin Martyr, held beliefs that later looked like precursors to Arianism, denying the eternal generation of the Son. Origen was also accused of Arian leanings for using terms like "second God," though his subordinationism is generally seen as closer to the Nicene position. Arius himself studied under Lucian of Antioch, inheriting a modified version of the teachings of Paul of Samosata.

Very little of Arius's own writings survive, mostly preserved in quotations chosen by his opponents to discredit him. His basic premise was that only God is self-existent and independent. Since the Son depends on the Father for his existence, Arius concluded the Son must be a creature. Arians often asked whether God created Jesus willingly or unwillingly, using this to argue that Jesus exists only because God chose to bring him into being. The Arian view held that the Logos—an inner attribute of God linked to wisdom—was a divine being created by the Father before the world, serving as the instrument of creation, and that the Son remained subordinate to the Father.