The First Ecumenical Council (Nicea, AD 325) established the doctrine that Jesus Christ is truly God, being of the same essence as the Father. The Second Ecumenical Council (Constantinople, AD 381) reiterated the deity of Christ, began to work through the relationship between Christ’s person and natures, and set forth clearly the deity of the Holy Spirit.
In the fifty years before the next ecumenical council met, theologians continued to investigate the relation between Christ’s divine person and His two natures. What particularly made necessary the meeting of the Council of Ephesus in AD 431 was the error of Nestorianism.
Mary, the God-bearer
The context in which Nestorius developed his views was a wrong view of Mary, the mother of Jesus, which many were promoting. They viewed her as an example of holiness, and some were suggesting that she was sinless. In time, the church viewed her as a co-mediator with Christ. For details about this development, the interested reader should consult a general church history book.1
Bearing on the Nestorian controversy is the fact that some began to call Mary theotokos, a Greek word meaning “God-bearer,” and sometimes translated as “mother of God.” Some in the church, reacting to the wrong views of Mary that were developing, also objected that this term exalted Mary too much. But other orthodox theologians, such as Athansius and Gregory Nazianzen, readily used the term, although they rejected wrong views of Mary. They did not think that Mary gave God His existence, or gave existence to Christ in His divine person or nature. They were simply insisting that Jesus Christ was truly and fully God, and recognizing that Mary gave birth to Him in the flesh.
Nestorius became the patriarch of Constantinople in AD 428. This made him the second most important religious figure in the world, second only to the bishop of Rome. Nestorius thought it wrong to use the term theotokos under any circumstances, even if one did not mean to venerate Mary. The correct term in his mind was Christotokos, bearer or mother of Christ.
The issue was not only about terms, it was about Christ Himself. Who was He? Nestorius agreed that Jesus was both God and man. In this respect, Nestorius was true to the Councils of Nicea and Constantinople.
But how can Christ be both God and man? The true answer is that Christ is one person (divine) who possesses two natures (divine and human), and that in His birth (incarnation) the divine Christ took to Himself a human nature from Mary. Nestorius’ answer was that Christ had two natures because He had two persons, one divine and the other human. He viewed Christ’s incarnation as a joining of the two persons, rather than a uniting of the human nature with the divine. While some scholars suggest that history has misrepresented him, this is what the church in that day understood him to teach.
Opposition to Nestorius
The bishop of Alexandria at this time was Cyril. After the bishop of Rome and the bishop of Constantinople, the bishops of Alexandria, Antioch, and Jerusalem held the next three most prominent positions in the church of that day.
Cyril argued that by speaking of Christ as two persons, Nestorius separated the natures of Christ, rather than distinguishing them. He also said that Nestorius undermined Christ’s divinity by rejecting theotokos. And he pointed out that this undermined the reality of the incarnation, the ability of Christ to save us, and the way in which He carried out that salvation.
A war of words followed. Cyril charged Nestorius with twelve errors. Nestorius countered with twelve accusations of his own, arguing that Cyril was basically Apollinarian (see Standard Bearer, October 15, 2020). The emperor deposed Nestorius, and realized the need for an ecumenical council to settle the matter.
Did Cyril and Nestorius understand each other, or did they talk past each other? Many are of the opinion that the latter is true. However, in the end, Nestorius’ view was condemned, and Cyril’s upheld. And the word theotokos won the day, even among the orthodox.
1 See Philip Schaff, History of the Christian Church, vol. 3, Nicene and Post-Nicene Christianity, A.D. 311-600 (Grand Rapids: Wm. B. Eerdmans, 1989 reprint), 410-428.