Great feast of the Nativity of Christ.
The Feast of the Nativity of Jesus is one of the most joyful days of the Orthodox Church. It ranks next to the greatest holiday, the Resurrection of Jesus. The Feast of the Birth of Jesus is also known as the "Incarnation of Christ." This means that Jesus became a man and came into the world to save us. We also refer to this joyous feast as Christmas.
On Christmas Day the service commemorates the birth of Christ in Bethlehem, the adoration of the Shepherds, and the arrival of the Wise Men with their gifts. The service held on this day is the Liturgy of Saint John Chrysostom.
The days following Christmas are associated with the Theotokos and Joseph. January 08 is the Synaxis of the Mother of God, and the first Sunday after the Feast commemorates “Joseph the Betrothed.” January 13 commemorates the Massacre of the Innocents, and January 14 the Circumcision of our Lord. The spirit of the The Nativity season extends to the celebration of Theophany (Epiphany), the feast commemorating the Baptism of our Lord in the Jordan River.