★ The Nativity according to the flesh of our Lord God and Saviour Jesus Christ
The Feast of the Nativity is one of the great Twelve Feasts of the Orthodox Church, and stands with Pascha as one of the two pillars of the Christian year. On this day the Church celebrates the unutterable mystery that the eternal Son and Word of God, consubstantial with the Father, took flesh of the Holy Spirit and the Virgin Mary and was born in Bethlehem of Judea, the City of David. He whom the heavens cannot contain was wrapped in swaddling clothes and laid in a manger, in fulfilment of the prophecies of Isaiah, Micah and the patriarchs.
The historical setting is given by the evangelists Matthew and Luke. In the days of the emperor Augustus, when Quirinius governed Syria and a decree of enrolment went out over the empire, Joseph and Mary went up from Nazareth to Bethlehem, and there the Mother of God brought forth her Son. The shepherds keeping watch over their flocks were the first to be called by an angel and a host of the heavenly powers singing, "Glory to God in the highest, and on earth peace, good will toward men." Wise men from the East, guided by a star, came afterwards bearing gifts of gold, frankincense and myrrh.
The choice of 25 December for the celebration is bound up with the early Church's response to the Roman feast of the Unconquered Sun, the Sol Invictus. Christ is proclaimed in the troparion as the true Sun of Righteousness, before whom the worshippers of the stars are taught to bow down to the Lord, the Dayspring from on high. The feast emphasises the wonder of the Incarnation: the One who is "one of the Holy Trinity" has entered into time and space, becoming a true human being while remaining unchangeably God, that we might be made partakers of the divine nature.
The feast is preceded by a forty-day fast and by two preparatory Sundays commemorating the Forefathers and the Fathers of Christ according to the flesh. The Royal Hours, the Vesperal Liturgy of Saint Basil and the Vigil are celebrated on the eve, and on the day itself the Divine Liturgy of Saint John Chrysostom is served. The festal period continues until 31 December, the Apodosis of the feast, with a forefeast and afterfeast that bind together the Synaxis of the Theotokos, the protomartyr Stephen and the Holy Innocents in the single mystery of God-with-us, Emmanuel.