...emphasizes the disunion between the human and divine natures of Jesus....holds that Christ had two loosely-united natures, divine and human...A brief definition of Nestorian Christology can be given as: "Jesus Christ, who is not identical with the Son but personally united with the Son, who lives in him, is one hypostasis and one nature: human."[1] Nestorius developed his Christological views as an attempt to rationally explain and understand the incarnation of the divine Logos, the Second Person of the Holy Trinity as the man Jesus Christ. He had studied at the School of Antioch where his mentor had been Theodore of Mopsuestia; Theodore and other Antioch theologians had long taught a literalist interpretation of the Bible and stressed the distinctiveness of the human and divine natures of Jesus.
...rejection of the title Theotokos ('Mother of God") for the Virgin Mary....Nestorius' teachings became the root of controversy when he publicly challenged usage of the long-used title Theotokos (Mother of God) for the Virgin Mary. He suggested that the title denied Christ's full humanity, arguing instead that Jesus had two loosely joined natures, the divine Logos and the human Jesus. As such he proposed Christotokos (Mother of Christ) as a more suitable title for Mary. [i.e. Jesus the Son of Mary as found in the Quran]
Nestorius' opponents found his teaching too close to the heresy of adoptionism – the idea that Christ had been born a man who had later been "adopted" as God's son. Nestorius was especially criticized by Cyril, Pope (Patriarch) of Alexandria, who argued that Nestorius' teachings undermined the unity of Christ's divine and human natures at the Incarnation.
In 431 Theodosius called the First Council of Ephesus. However, the council ultimately sided with Cyril, holding that Christ is one subsistence and nature, and that the Virgin Mary is the mother of God. The council accused Nestorius of heresy, and deposed him as patriarch.[3] Nestorianism was officially anathematized, a ruling reiterated at the Council of Chalcedon in 451. However, a number of churches, particularly those associated with the School of Edessa, supported Nestorius – though not necessarily his doctrine – and broke with the churches of the West. Many of Nestorius' supporters relocated to Sassanid Persia, home to a vibrant but persecuted Christian minority
In 424, the Persian Church declared itself independent of the Byzantine and all other churches, in order to ward off allegations of foreign allegiance. Following the Nestorian Schism, the Persian Church increasingly aligned itself with the Nestorians, a measure encouraged by the Zoroastrian ruling class. The Persian Church became increasingly Nestorian in doctrine over the next decades, furthering the divide between Chalcedonian Christianity and the Nestorians. In 486 the Metropolitan of Nisibis, Barsauma, publicly accepted Nestorius' mentor, Theodore of Mopsuestia, as a spiritual authority. In 489 when the School of Edessa in Mesopotamia was closed by Byzantine Emperor Zeno for its Nestorian teachings, the school relocated to its original home of Nisibis, becoming again the School of Nisibis, leading to a wave of Nestorian immigration into Persia. The Persian patriarch Mar Babai I (497–502) reiterated and expanded upon the church's esteem for Theodore, solidifying the church's adoption of Nestorianism.[4]
Now firmly established in Persia, with centers in Nisibis, Ctesiphon, and Gundeshapur, and several metropolitan sees, the Nestorian Persian Church began to branch out beyond the Persian Sassanid Empire. However, through the 6th century the church was frequently beset with internal strife and persecution from the Zoroastrians. The infighting led to a schism, which lasted from 521 until around 539, when the issues were resolved. However, immediately afterward Roman-Persian conflict led to the persecution of the church by the Sassanid King Khosrau I; this ended in 545. The church survived these trials under the guidance of Patriarch Mar Abba I, who had converted to Christianity from Zoroastrianism.[4]
The church emerged stronger after this period of ordeal, and increased missionary efforts farther afield. Missionaries established dioceses in the Arabian Peninsula and India (the Saint Thomas Christians). They made some advances in Egypt, despite the strong Oriental Orthodox (Monophysite) presence there.[5] Missionaries entered Central Asia and had significant success converting local Tartar tribes. Nestorian missionaries were firmly established in China during the early part of the Tang Dynasty (618–907); the Chinese source known as the Nestorian Stele records a mission under a Persian proselyte named Alopen as introducing Nestorian Christianity to China in 635. Following the Muslim conquest of Persia, completed in 644, the Persian Church became a protected dhimmi community under the Rashidun Caliphate. The church and its communities abroad flourished under the Caliphate; by the 10th century it had fifteen metropolitan sees within the Caliphate's territories, and another five elsewhere, including in China and India
