As the Christian Church grew and developed, the complexity of its understanding of the
Triune God and the
person of Christ also grew and developed. It's important to understand the controversies of
Christology regarding its parallel with the
organisation of the church, as they are ideally united as one, the latter seen as the body of
Christ. In 325, the issue of how to reconcile the claims of
monotheism with the assertion of the divinity of Jesus of Nazareth was largely settled at the
First Ecumenical Council held at
Nicaea. Especially among the Greek-speaking Christians, attention turned to how to understand how the second person of the Trinity became incarnate in the person of Jesus Christ. However, neither the Nicene Creed nor the
canons of the Council provided a detailed explanation of how God became human in the person of Jesus, leaving the door open for speculation. One such theory of how the human and divine interact in the person of Jesus was put forward by the
Patriarch of Constantinople,
Nestorius (c. 386–451). Nestorius, a student of the
Antiochene school of theology, taught that in the incarnation two distinct
hypostases ("substances" or, as Nestorius' critics such as
John Cassian and
Cyril of Alexandria employed the term, "persons") were conjoined in Jesus Christ: one human (the man) and one divine (the Word). Thus, Mary should not be considered the God-bearer (
Theotokos) since she only contributed to and bore the human nature of Christ, making her the
Christotokos. In 431, Nestorius and his teachings were condemned by the
Third Ecumenical Council, held in
Ephesus, which defined the
Church of the East. The Council of Ephesus did not answer the question of how the human and divine interrelated in the person of Christ. It seemingly rejected any attempted answer that stressed the duality of Christ's natures to the expense of his unity as a single
hypostasis (understood to mean "person"). ==Eutyches and Chalcedon==