The Glorious Feast of Nativity: 7 January? 29 Kiahk? 25 December?
The first Church did not celebrate the birth of Christ. And the actual date of his birth was and still is unknown. The earliest known indication to such a celebration comes in a passing statement by St. Clement of Alexandria who mentions that the Egyptians of his time celebrated the Lord's birth on May 20. At the end of the 3rd century, the Western Churches celebrated it in the winter, and this was only accepted in Rome in the middle of the 4th century.
Around that time it was agreed by the Church all over the world to celebrate the nativity of our Lord Jesus Christ on 25 December (29 Kiahk in the Coptic calendar), most probably to take the place of a pagan feast that even Christians continued to celebrate until tahen.
At that time, and until the sixteenth century, the civil calendar in use the world over was the Julian calendar, introduced by Julius Caesar in the year 46 B.C. This calendar considered the year to be 365.25 days 4 and thus had a leap year every four years, just like the Coptic calendar. Therefore, until the sixteenth century, 25 December coincided with 29 Kiahk, as the date of the celebration of the Lord's nativity.
Incarnation of the Word Jesus
Upon the Feast of the Incarnation of the Word, it is important to reflect upon the birth of the Lord Jesus Christ and what He represents. St. John in His Holy Gospel wrote, "In the beginning was the Word, and the Word was with God, and the Word was God." (1:1) and the Apostle also wrote, "The Word became flesh and dwelt among us." (1:14) Through these Holy Scriptures we learn that the Lord Jesus Christ is God, for He was with God before all times. This is the reason we recite, "We believe in one Lord Jesus Christ, the Only begotten Son of God…" in the Nicene Creed.
The Nativity of Christ - A New Covenant
The birth of our Lord Jesus Christ marks the beginning of a New Covenant between God and man, a covenant previously and purposefully foreshadowed and prepared for by a prior covenant. In order to understand and appreciate the New Covenant that God has instituted with humanity, it is necessary to take a close look at the old one. The Old Covenant was between God and Israel "And I will establish My covenant between Me and you and your descendants after you in their generations, for an everlasting covenant, to be God to you and your descendants after you" (Genesis 17:7).
The New Covenant, however, is established between God and any person who will receive the Son of God "But as many as received Him, to them He gave the right to become children of God, to those who believe in His name who were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God (John 1:12,13).