Nestorianism

Nestorianism refers to the Christological positions associated with Nestorius (c. 386–450), who served as Patriarch of Constantinople from 428 to 431. It emphasizes a strong distinction between the divine Word (Logos) and the human Jesus in the person of Christ, and is often linked to the claim that Mary bore Christ (Christotokos) rather than God (Theotokos). In its more controversial readings, proponents were understood to speak of two distinct persons in the Incarnation, united in one Jesus, a view opponents condemned as denying the unity of Christ's person and nature. The Council of Ephesus in 431 condemned Nestorianism and affirmed Theotokos for Mary; Nestorius was deposed and exiled.

The condemnation did not erase the movement; its adherents formed the Church of the East, centered in the Sasanian Empire and known historically as the Nestorian Church. It developed a distinct East Syriac liturgy and theology and carried its missionary outreach along the Silk Road into Persia, Central Asia, and China. The Nestorian Stele (Xi’an, circa 781) records the presence of East Syriac Christians in Tang Dynasty China. While the tradition is described as dyophysite (two natures), scholars debate how the unity of Christ is described in its terminology.

In modern times, the term Nestorianism is largely a historical designation; scholarship distinguishes Nestorius's writings from later East Syriac formulations, and the label is used cautiously to avoid oversimplification. The Church of the East survived into the modern era, giving rise to the Assyrian Church of the East, the Chaldean Catholic Church (in communion with Rome), and the Ancient Church of the East, among others.