Nestorius (386-450 AD) rejected the traditional doctrine of the Incarnation by implicitly denying the hypostatic union of human and divine natures in the one divine person of Jesus. This denial was characterized notably by the rejection of the title “Theotokos” (“God bearer” or “Mother of God”) for the mother of Jesus. He claimed that Mary was the mother of Christ’s human nature but not the mother of God and concluded that only Jesus the man suffered and died on the cross.
From the definitions and condemnations of the Arian heresy of the fourth century several things resulted. The divinity of Christ and the reality of his Incarnation were clearly established in the minds of the faithful. Consequently, the exaltation and veneration of Mary by the faithful became more widespread. Since Jesus was truly God and Mary was his mother, she was venerated with the title of Theotokos. This veneration was especially popular in the East.
Controversy erupted in 428 when Nestorius, the newly installed bishop of Constantinople, attacked the title Theotokos from the pulpit in the cathedral on Christmas day, claiming that Mary was the mother of Christ but not the mother of God. He stated that to call Mary the Mother of God implied that the divine nature was born of a woman, thus making her a goddess.
Immediately his teaching was attacked by the laity and the clergy of Constantinople. When word spread of this new doctrine, neighboring bishops condemned him outright. Chief among his critics was bishop Cyril of Alexandria who responded, “I am astonished that the question should ever have been raised as to whether the Holy Virgin should be called Mother of God, for it really amounts to asking, is her Son God or is he not?” He wrote to Nestorius condemning the heretical.aspects of his doctrine and asking him to explain and defend himself. The reply betrayed even further the depth of his heresy.
Cyril sent his personal correspondence with Nestorius as well his own five-book response titled Against Nestorius to Pope Celestine in Rome for the pontiff’s decision. The Holy Father gave a general condemnation of the teaching of Nestorius regarding Mary’s divine maternity and commanded him to recant within ten days. Cyril was to receive the recantation or depose Nestorius. Far from submitting, Nestorius demanded an ecumenical council and proclaimed his beliefs more loudly than ever.
While claiming to believe in one Christ in two natures, his explanation described the union of two distinct persons: “He who was formed in the womb of Mary was not God himself, but God assumed him. Through him that bears I worship him who is born.” A mother cannot bear a son older than herself, he contended. Therefore, Mary did not give birth to the incarnate Word of God, only to Jesus, the temple or vessel of God. Rejecting the orthodox sense of Theotokos, he opted instead for Christokos (“Mother of Christ”), saying that he could never bring himself to call the Christ-child God. Nestorius concluded that it was not God who suffered and died on the cross, but only the man Jesus.
The main problem with Nestorius is that free acts originate from persons and not from natures. What Nestorius called “natures” should have been called “persons.” His error was to divide Christ into two persons – human and divine. Christ is only one Person and Mary is the mother of that Person. Mothers give birth to persons and not natures.
Besides St. Cyril, many other clergy and laymen rose to defend the divine maternity of Mary against the attack of Nestorius. Among these were Philip of Side, Proclus, Leo of Rome, and the layman Eusebius, later to become a bishop. Eusebius, while still a lawyer, is said to have risen from the congregation after Nestorius’ initial Christmas homily and to have indignantly responded, “The eternal Word begotten before the ages had submitted also to be born a second time.”
With Nestorius holding firm to his position, the emperor proposed to have a council meet in Ephesus to decide the matter once and for all. The council opened in the name of Pope Celestine I on June 22, 431.
Nestorius, who refused to attend, had his teachings anathematized, along with all who held communion with him, and he was deposed as bishop of Constantinople. Mary was officially proclaimed Mother of God to the delight of the faithful of Ephesus.
The controversy created by Nestorius made it obvious that a clearer terminology was needed to define the doctrine of the Incarnation which protected the divinity as well as the humanity of Christ. The solution, arrived at by Pope St. Leo the Great, was the use of the word “person,” for which there was no well-defined concept before that time. Leo summed it up in his Tome 20 years after the Council of Ephesus: Each nature performs the actions proper to it, but every action is performed by the one person, Jesus the Word of God.
Today most Protestant denominations display an element of Nestorianism. Protestants typically reject the title “Mother of God” while echoing Nestorius’ contention that a son cannot be older than his mother. They find it difficult to say that God was born in Bethlehem, that God suffered and died on the cross at Calvary. Many Protestant theologians, on the other hand, recognize this element of Nestorianism and assent to the title “Mother of God,” though they use it only infrequently.