A myth pushed by popular and once prestigious media is that orthodox church teaching on Christ is practically an invention of Constantine and some shadowy Magisterium. Such revision of history transforms the Council of Nicaea into an incense-filled room more intent on suppressing the truth or inventing truth than in guarding it and propagating it.
Yet the truth of the matter is that church teaching on Christology developed rapidly long before Nicaea and the rest of the ecumenical councils. Really this development began with the risen Christ teaching the Apostles about himself from the scriptures before the Ascension. And the Christological teaching of the Apostles and their successors wasn’t done in the shadows but in the churches and even at times in the streets. That is clear not only from the New Testament but also from writings of the Apostolic and later Fathers. In letters and sermons read and preached to congregations, we can see that catholic Christology developed rapidly and openly.
Thus began the Patristics paper I was working on when I was not blogging here. (Sorry I almost disappeared for a while, but priorities….) With Christmas nearing, we will be sure to see more rubbish that God becoming man – that baby in the manger being God Incarnate – was not a marvelous loving act of God but an invention of the later church. So now is a good time to note that the church got it right very early: that baby was both God and man, the Christ.
Perhaps the best source on that in the generation after the apostles and the writing of what became the New Testament is St. Ignatius. As he was being led on his long trip to the lions and martyrdom early in the 2nd Century, he wrote a number of letters to churches, of which we have six. Impending death can aid candor, and that seemed to be the case with Ignatius. Among the subjects about which he was very frank was the deity and manhood of Christ. Note that the six letters addressed whole congregations, not just church leaders.
From my paper:
John’s Gospel was the most clear and developed of the four in proclaiming the deity of Christ. His pupil Ignatius is even more straightforward. To the Ephesians, he repeatedly calls Jesus “our God” and even writes that it is “God’s blood” that saves them and stirs them to sanctification. He also calls Jesus “our God” when writing the church at Rome, and in begging the Romans not to intervene to prevent his martyrdom he asks, “Let me imitate the Passion of my God.” To the Smyrnaeans, he praises “Jesus Christ, the God who has granted you such wisdom” and later calls him “the Christ God.”
At the same time, he assertively teaches the other side of the Incarnation – the humanity of Christ. He did not give room to those who diminish either the deity or humanity of Christ and was especially eloquent in teaching both sides of the Incarnation to the Ephesian church:
There is only one physician – of flesh yet spiritual, born yet unbegotten, God incarnate, genuine life in the midst of death, sprung from Mary as well as God, first subject to suffering then beyond it – Jesus Christ our Lord. 
The heresy of Docetism, that taught that Jesus only seemed to be a man, goaded Ignatius to be every bit as adamant about the manhood of Christ as he was about the deity of Christ. To the Trallians, he wrote that Jesus “was really born, ate, and drank; was really persecuted under Pontius Pilate; was really crucified and died, . . . was really raised from the dead . . . apart from whom we have no genuine life.”
Thus just a decade or two after the death of the last Apostle, St. John, Ignatius got it that Jesus Christ was completely God from eternity and completely man from his conception and birth.
And that is the theme of Christmas, is it not? That babe in the manger was Very God of Very God and “the Word made flesh” for us and for our salvation. If one was blessed enough to attend a Christ-mass celebrated by a church father, one likely to hear this, the Incarnation, preached.
It just so happens that Augustine’s preaching of the Incarnation on Christmas Day will be the subject of a talk I will give on St. John’s Day, December 27th in Texas. Get ahold of me if you want more details.