In the 5th century in Christianity, there were many developments which led to further fracturing of the State church of the Roman Empire. Emperor Theodosius II called two synods in Ephesus, one in 431 and one in 449, that addressed the teachings of Patriarch of Constantinople Nestorius and similar teachings. Nestorius had taught that Christ's divine and human nature were distinct persons, and hence Mary was the mother of Christ but not the mother of God. The Council rejected Nestorius' view causing many churches, centered on the School of Edessa, to a Nestorian break with the imperial church. Persecuted within the Roman Empire, many Nestorians fled to Persia and joined the Sassanid Church.American Board of Commissioners for Foreign Missions (1857), p. 89. By the end of the 5th century, the global Christian population was estimated at 10-11 million. In 451 the Council of Chalcedon was held to clarify the issue further. The council ultimately stated that Christ's divine and human nature were separate but both part of a single entity, a viewpoint rejected by many churches who called themselves miaphysites. The resulting schism created a communion of churches, including the Armenian, Syrian, and Egyptian churches, that is today known as Oriental Orthodoxy.Bussell (1910), p. 346. In spite of these schisms, however, the imperial church still came to represent the majority of Christians within the Roman Empire.Latourette (1975), p. 183.
At the end of the 4th century the Roman Empire had effectively split into two states although its economy and the Church were still strongly tied. The two halves of the empire had always had cultural differences, in particular exemplified by the widespread use of the Greek language in the Eastern Empire and the more limited use of Greek in the West (Greek was used in the West but Latin was displacing it as the spoken vernacular. By the 5th century scholars in the West had begun to abandon Greek in favor of the use of Latin. The Church in Rome, in particular, began to encourage the use of Latin in the western provinces and published Jerome's Vulgate, the first authorized translation of the Bible in Latin.
At the same time as these changes were taking place the Western Empire was beginning to decay rapidly. Germanic tribes, particularly the Goths, gradually conquered the western provinces. The Arian Germanic tribes established their own systems of churches and bishops in the western provinces but were generally tolerant of those who chose to remain loyal to the imperial church.Anderson (2010), p. 604.Amory (), pp. 259–262.
Ecumenical councils The Council of Ephesus in 431 and the Council of Chalcedon in 451 led to the schism with Church of the East and the schism with the Miaphysite churches. The latter schism established what is today known as Oriental Orthodoxy.
First Council of Ephesus Theodosius II called a council to settle the Nestorian controversy. Nestorius, Patriarch of Constantinople, opposed use of the term Theotokos (Greek Η Θεοτόκος, "God-bearer")."Nestorius." Cross, F. L., ed. The Oxford dictionary of the Christian church. New York: Oxford University Press. 2005 This term had long been used by orthodox writers, and it was gaining popularity along with devotion to Mary as Mother of God. He reportedly taught that there were two separate persons in the incarnate Christ, though whether he actually taught this is disputed. Cyril of Alexandria charged that this teaching of Nestorius implied that there had been in fact two Jesus Christs; one Christ was a man born of the virgin Mary and the other was divine and not born but also Jesus Christ.
Cyril of Alexandria regarded the embodiment of God in the person of Jesus Christ to be so mystically powerful that it spread out from the body of the God-man into the rest of the race, to reconstitute human nature into a graced and deified condition of the saints (Jesus Christ as the new Adam), one that promised immortality and transfiguration to believers. Nestorius, on the other hand, saw the incarnation as primarily a moral and ethical example to the faithful, to follow in the footsteps of Jesus. Cyril repeatedly stressed the simple idea that it was God who walked the streets of Nazareth (hence Mary was Theotokos or Mother of God), and God who had appeared in a transfigured humanity (see the theophany). Nestorius spoke of the distinct 'Jesus the Man' and 'the divine Logos' in ways that Cyril thought were too dichotomous, widening the ontological gap between man and God in a way that would annihilate the person (hypostasis) of Christ a position termed dyophysite.CATHOLIC ENCYCLOPEDIA: Nestorius and Nestorianism
The council deposed Nestorius, repudiated Nestorianism, proclaiming the Virgin Mary as the Theotokos.
After quoting the Nicene Creed in its original form, as at the First Council of Nicaea, without the alterations and additions made at the First Council of Constantinople, it declared it "unlawful for any man to bring forward, or to write, or to compose a different (ἑτέραν) Faith as a rival to that established by the holy Fathers assembled with the Holy Ghost in Nicæa."canon 7
Council of Chalcedon The Council of Chalcedon took place from October 8 to November 1, 451, at Chalcedon (a city of Bithynia in Asia Minor). It was the fourth of the first seven Ecumenical Councils and is therefore recognized as infallible in its dogmatic definitions by the Roman Catholic and Eastern Orthodox churches. Chalcedon was called to address concerns first raised in November 448, at a synod at Constantinople, which condemned Eutyches for unorthodoxy. An archimandrite of a large Constinapolitan monastery,"Eutyches" and "Archimandrite." Cross, F. L., ed. The Oxford dictionary of the Christian church. New York: Oxford University Press. 2005 Eutyches taught a Christological position at the opposite extreme from that of Nestorius,"Latrocinium." Cross, F. L., ed. The Oxford dictionary of the Christian church. New York: Oxford University Press. 2005 namely that Christ was not consubstantial with humanity."Monophysitism." Cross, F. L., ed. The Oxford dictionary of the Christian church. New York: Oxford University Press. 2005 In order to settle the issue, the Second Council of Ephesus was held in 449, at which Eutyches was exonerated and returned to his monastery. Although intended to be an ecumenical council, this council was not called with enough notice for the Western bishops to attend, and was subsequently labeled a "robber council" by the Council of Chalcedon.
The Council of Chalcedon repudiated Eutyches and his doctrine of monophysitism, described and delineated the "Hypostatic Union" and two natures of Christ, human and divine. It also adopted the Chalcedonian Creed, which describes the "full humanity and full divinity" of Jesus, the second person of the Holy Trinity.
Schism in the East
Nestorianism
Nestorian churches are Eastern Christian churches that keep the faith of only the first two ecumenical councils, i.e., the First Council of Nicaea and the First Council of Constantinople. "Nestorian" is an outsider's term for a tradition that predated the influence of Nestorius. Thus, "Assyrian Church of the East" is a more neutral term. The Nestorian Schism was the first major schism of the Eastern Churches and was addressed with the Council of Ephesus.
Oriental Orthodoxy
Eastern Orthodoxy strives to keep the faith of the seven Ecumenical Councils. In contrast, the term "Oriental Orthodoxy" refers to the churches of Eastern Christian traditions that keep the faith of only the first three ecumenical councils — the First Council of Nicaea, the First Council of Constantinople and the Council of Ephesus — and rejected the dogmatic definitions of the Council of Chalcedon. It is sometimes called the Greek Orthodox to distinguish it from the Coptic Orthodox Patriarchate of Alexandria. In Egypt, members of the Greek Orthodox Patriarchate were also called Melkite, because they remained in communion with the Patriarch of Constantinople.
Oriental Orthodox is also sometimes referred to as "monophysites", "non-Chalcedonians", or "anti-Chalcedonians", although today the Oriental Orthodox Churches denies that it is monophysite and prefers the term "miaphysite" to denote the "joined" nature of Jesus. The dogma chosen by the Oriental Orthodox was interpreted to express that Jesus Christ had two natures (both human and divine) that were unified hypostatically into a one single nature. This was interpreted from the Byzantine position to be an argument that greatly diminished the human reality of Christ, by also making the human will of Christ one not of freewill.Vladimir Lossky theology is the most widely accepted and or followed of all modern Orthodox theologians
Those who disagreed with the findings of the Council of Chalcedon are today known as the Coptic Orthodox Church of Alexandria. This included the Ethiopian Orthodox Tewahedo Church and the Armenian Orthodox church. There was a similar split in Syria (Patriarchate of Antioch) into the Greek Orthodox Church of Antioch and the Syriac Orthodox Church.
Post-Nicene Fathers
Late Antique Christianity produced a great many renowned Fathers who wrote volumes of theological texts, including Augustine, Gregory Nazianzus, Cyril of Jerusalem, Ambrose of Milan, Jerome, and others. What resulted was a golden age of literary and scholarly activity. Some of these fathers, such as John Chrysostom and Athanasius, suffered exile, persecution, or martyrdom from heretical Byzantine Emperors. Many of their writings are translated into English in the compilations of Nicene and Post-Nicene Fathers.
The Church Fathers, Early Church Fathers, or Fathers of the Church are the early and influential theologians and writers in the Christian Church, particularly those of the first five centuries of Christian history. The term is used of writers and teachers of the Church, not necessarily saints. Teachers particularly are also known as doctors of the Church, although Athanasius called them men of little intellect.Athanasius, On the Incarnation 47
Greek Fathers Those who wrote in Greek are called the Greek (Church) Fathers. Famous Greek Fathers include: Irenaeus of Lyons, Clement of Alexandria, the heterodox Origen, Athanasius of Alexandria, John Chrysostom, Cyril of Alexandria and the Cappadocian Fathers (Basil of Caesarea, Gregory Nazianzus, Peter of Sebaste and Gregory of Nyssa.
Cappadocian Fathers
The Cappadocians promoted early Christian theology and are highly respected in both Western and Eastern churches as saints. They were a 4th-century monastic family led by Saint Macrina the Younger to provide a central place for her brothers to study and meditate, and also to provide a peaceful shelter for their mother. Abbess Macrina fostered the education and development of three men who collectively became designated the Cappadocian Fathers: Basil the Great who was the second oldest of Macrina's brothers (the first being the famous Christian jurist Naucratius) and eventually became a bishop; Gregory of Nyssa who also became a bishop of the diocese associated thereafter with his name; and Peter of Sebaste who was the youngest of Makrina's brothers and later became bishop of Sebaste.
These scholars along with Gregory Nazianzus set out to demonstrate that Christians could hold their own in conversations with learned Greek-speaking intellectuals and that Christian faith, while it was against many of the ideas of Plato and Aristotle (and other Greek Philosophers), was an almost scientific and distinctive movement with the healing of the soul of man and his union with God at its center—one best represented by monasticism. They made major contributions to the definition of the Trinity finalized at the First Council of Constantinople in 381 and the final version of the Nicene Creed which was formulated there.