Arius in the context of "Heresy"

Arianism (Koine Greek: Ἀρειανισμός, Areianismós) is a Christological doctrine that rejects the traditional notion of the Trinity, teaching that Jesus was created by God and is therefore distinct from God. It is named after its proponent Arius (250 or 256 – 336) and is regarded as heretical by most modern mainstream branches of Christianity. Arianism is held by a minority of modern denominations, although some of these groups espouse related doctrines such as Socinianism, and others avoid the term "Arian" because of its historically negative connotations. Modern denominations sometimes associated with the teaching include Jehovah's Witnesses, some churches within the Churches of Christ (among them the movement's founder, Barton W. Stone), and certain Hebrew Roots Christians and Messianic Jews, although many Messianic Jews adhere to Nicene Christianity. The Arian view is also held by The Church of Jesus Christ of Latter Day Saints, although the theology is more distinct in key ways.

It is first attributed to Arius, a Christian presbyter who preached and studied in Alexandria, Egypt, although it developed out of various preexisting strands of Christianity which differed from later Nicene Christianity in their view of Christology. Arian theology holds that Jesus Christ is the Son of God, who was begotten by God the Father with the difference that the Son of God did not always exist but was begotten/made before time by God the Father; therefore, Jesus was not coeternal with God the Father, but nonetheless Jesus began to exist outside time.

Athanasius I of Alexandria (c. 296–298 – 2 May 373), also called Athanasius the Great, Athanasius the Confessor, or, among Coptic Christians, Athanasius the Apostolic, was a Christian theologian and the 20th patriarch of Alexandria (as Athanasius I). His intermittent episcopacy spanned 45 years (c. 8 June 328 – 2 May 373), of which over 17 encompassed five exiles, when he was replaced on the order of four different Roman emperors. Athanasius was a Church Father, the chief proponent of Trinitarianism against Arianism, and a noted Egyptian Christian leader of the fourth century.

Conflict with Arius and Arianism, as well as with successive Roman emperors, shaped Athanasius' career. In 325, at age 27, Athanasius began his leading role against the Arians as a deacon and assistant to Bishop Alexander of Alexandria during the First Council of Nicaea. Roman Emperor Constantine the Great had convened the council in May–August 325 to address the Arian position that the Son of God, Jesus of Nazareth, is of a distinct substance from the Father. Three years after that council, Athanasius succeeded his mentor as Patriarch of Alexandria. In addition to the conflict with the Arians (including powerful and influential Arian churchmen led by Eusebius of Nicomedia), he struggled against the Emperors Constantine, Constantius II, Julian the Apostate and Valens. He was known as Athanasius Contra Mundum (Latin for 'Athanasius Against the World').

Arianism (Koine Greek: Ἀρειανισμός, Areianismós) is a Christological doctrine that rejects the traditional notion of the Trinity, teaching that Jesus was created by God and is therefore distinct from God. It is named after its proponent Arius (250 or 256 – 336) and is regarded as heretical by most modern mainstream branches of Christianity. Arianism is held by a minority of modern denominations, although some of these groups espouse related doctrines such as Socinianism, and others avoid the term "Arian" because of its historically negative connotations. Modern denominations sometimes associated with the teaching include Jehovah's Witnesses, some churches within the Churches of Christ (among them the movement's founder, Barton W. Stone), and certain Hebrew Roots Christians and Messianic Jews, although many Messianic Jews adhere to Nicene Christianity. The Arian view is also held by The Church of Jesus Christ of Latter-day Saints, although the theology is more distinct in key ways.

It is first attributed to Arius, a Christian presbyter who preached and studied in Alexandria, Egypt, although it developed out of various preexisting strands of Christianity which differed from later Nicene Christianity in their view of Christology. Arian theology holds that Jesus Christ is the Son of God, who was begotten by God the Father with the difference that the Son of God did not always exist but was begotten/made before time by God the Father; therefore, Jesus was not coeternal with God the Father, but nonetheless Jesus began to exist outside time.