In the late fourth century, the meaning of Theophany began to shift from Christ’s birth to His baptism, thereby emphasizing the divine or theophanic character of this feast over its earlier more human aspect. The Nativity, which falls only twelve days previous, formed a fitting complement to the Theophany by emphasizing the human nature of Christ through the celebration of His birth.
Like the Ascension, the Theophany was observed locally in some churches before the introduction of the Nativity. The Theophany’s connotations as the birth feast lingered, as Jerome’s homilies indicate, so this probably accounts for the later adoption of the Nativity at Alexandria (sometime around 430) and at Jerusalem slightly later than at Alexandria. It is also probably that the Council of Ephesus of 431 and the Formulary of 433 – an attempted compromise between the Church and Nestorian views of the nature of Christ – encouraged the acceptance of the Nativity in these cities.
On December 20, 386 or 388, St. John Chrysostom announced in a sermon to his faithful that in that year for the first time Antioch would be celebrating the feast of the Nativity of our Lord on the 25th of December, independently from the feast of the Theophany. He also added that this feast “can without mistake be called the mother of all the feasts”, for “from it the Theophany, the holy Pasch, the Ascension and the Pentecost have their origin and foundation. If Christ had not been born in the flesh, neither could he have been baptized, and we would not have Theophany; had he not been crucified – we would not have the Pasch; had he not sent the Holy Spirit – we would not have Pentecost. Thus, from the Nativity of Christ, all the other feasts flow like different streams from the same source. This feast justly occupies first place not only because of this, but also because the event which this day commemorates is, of all events, the most worthy of wonder.”
Truly, Christ’s Nativity is the most significant event in the history of the human race. This event inaugurated the Christian era and became the point of reference from which we date the events of world history.
For the first three centuries, as I have stated, the Christians did not have a separate feast of the Nativity of Christ. At that time the only feast known was the Theophany, which was celebrated on the 6th of January. This feast included the Lord’s Nativity and Baptism, celebrating the manifestation of God in the flesh to humankind.