As the 5th century went on a new false teaching arose. This false teaching so emphasized the divinity of Jesus Christ that his humanity was reduced to nothing. This may seem strange to us. We naturally believe that Jesus Christ is a human being. But in ancient times, there was a strong sense that God could not really become human. People who were raised on Greco-Roman philosophy could not believe that God Himself could be hungry, thirsty or tired. This was inconsistent with their notion of God. They would say that all of Christ’s physical needs were a kind of “show”. Some even said that when Jesus walked he did not leave footprints in the sand. And, of course, Jewish people could not accept that the Messiah would die a painful, shameful death on the cross. Again, a ‘play acting’ Jesus could not truly transform humanity from within. This is why the Church has always held on to the humanity of Christ. In other words, Jesus Christ had to be truly God to conquer sin, death and the devil, but he also had to be truly human to help us. A council was called in Chalcedon to address these issues. The council said that although there is only one divine person in Jesus Christ, there are two natures, divine and human. Therefore, this council was defending the humanity of Jesus Christ.There are Christians who do not accept the Council of Chalcedon. These people affirmed that there is only “one divine nature” in Jesus Christ. The Christians are sometimes called “monophoysite” (mono-physis = one nature). They are also called non-Chalcedonian Christians or Oriental Orthodox, and include the Coptic, Ethiopian and Armenian churches. However, as a result of further study and ecumenical dialogue beginning in the 20th century, theologians have come to see the difference between the Chalcedonian and non-Chalcedonian Christians as linguistic verbal differences rather than differences in belief. We can hope that God will lead us to heal this schism.
Some people thought that this stress on the two natures was a falling back to the Nestorian heresy which said there was only a connection between the divinity and humanity of Christ. To make it clear that the Council of Chalcedon was not Nestorian, the Emperor Justinian (It is interesting to note that the Emperor Justinian was a skilled theologian, as his activities on behalf of the church show. It was a strong tradition in the Eastern (Byzantine) Empire that laymen and women could be theologians. This held true to the very end of the Eastern Empire. In the West, theology early on became a matter for clergy, not for lay people. Justinian was also renowned as a builder. He commissioned the building of Hagia Sophia (Holy Wisdom) Basilica in Constantinople [now Istanbul] which for many centuries was the greatest church in Christendom. After the Muslims conquered it, it became a mosque and is now a museum. Justinian also commissioned the building of St. Catherine’s Monastery at the foot of Mt. Sinai, one of the oldest, still functioning monasteries in the Christian world.) called a council in 553 to reiterate the Orthodox teaching that Jesus Christ is one, divine person in the two natures, human and divine. To express this poetically Justinian wrote the hymn “Only-begotten Son” which we sing at ever Divine Liturgy.
Only-begotten Son and immortal Word of God, Who for our salvation didst will to be incarnate of the holy Theotokos and ever-virgin Mary, Who without change didst become man and wast crucified, Who art one of the Holy Trinity, glorified with the Father and the Holy Spirit: O Christ our God, trampling down death by death, save us!
We can see, then, that the 1st to 5th ecumenical councils were concerned with showing how Jesus Christ is related to God and humanity. This was not for the sake of theological controversy or debate, but rather to be sure that Jesus Christ is truly our Savior.