The Epiphany is the culmination of the Christmas holiday season. Liturgically, it is a specific feast day that comes on January 6, which has diverse reference points in different liturgical traditions. What is common to all, however, is the celebration of the Incarnation as God's manifestation of Himself to the world.
Jesus in the flesh, in His concrete, visible, audible, tangible presence, is the definitive revelation of God wherein He "speaks" (and gives) the fullness of Himself in the Person of the Son, the Word made flesh. January 6 celebrates the "public" appearance of Christ, the "beginning" of the communication of Himself to others beyond the immediate circle of Mary, Joseph, and the shepherds (the prior presence of the shepherds makes Christmas itself a kind of "epiphany" which is a special gift to the poor and lowly).
In the Latin Western tradition, the Epiphany is linked to the specific event of the arrival of the Magi. These kings or sages (or perhaps both) "from the East" represent the Gentiles, the peoples of the earth beyond Israel and "outside" the particularity of the historical Covenant of Abraham and Moses, whom God has destined to be united with the fulfillment of Israel in His Son.
From the beginning, Jesus is acknowledged as God revealing His glory for the whole human race, and the center of all creation.
COLLECT for Epiphany, Roman Rite:
O God, who on this day
revealed your Only Begotten Son to the nations
by the guidance of a star,
grant in your mercy
that we, who know you already by faith,
may be brought to behold the beauty of your sublime glory
Through our Lord Jesus Christ, your Son,
who lives and reigns with you in the unity of the Holy Spirit,
one God, for ever and ever.
Currently, the Sunday following the Epiphany is a distinct feast day in the West, the "Baptism of the Lord," which marks Jesus's baptism in the Jordan by John. This manifestation event is Trinitarian, with the voice of the Father and the descent of the Holy Spirit in the appearance of a dove.
For the Byzantine tradition, and most of the ancient liturgical traditions of the East, January 6 celebrates this baptismal event. This is the Theophany in a very special sense, not simply as the beginning of Jesus's public ministry, but as the first public manifestation of the mystery of the Trinity. It is also full of an abundant symbolic resonance for the history of salvation, the humanity of Christ, and the whole of creation.
TROPARION: At Your baptism in the Jordan River, O Christ, the worship due to the Holy Trinity was made manifest, for the voice of the Father bore You witness by calling You "Beloved Son," and the Holy Spirit, in the form of a Dove, confirmed the immutability of this declaration. O Christ God who came forth and filled the world with light, glory to You!
KONTAKION: Today You have appeared to the world, O Lord, and Your light has shone upon us who, realizing who You are, sing to You a hymn of praise. Inaccessible light, You have come and made yourself known!
O Creator of the world, You appeared in the world in order to shine upon those who live in darkness. O Merciful One, glory to You!
O our Saviour, through the greatness of Your mercy, You cleansed the sinners and the publicans, and now Your light shines upon those who live in darkness. Glory to You!
The many Christmas seasonal traditions have as one of their common themes Christ as the true light who has come into the world, the light who dispels the darkness of sin and death, the light of the nations, that light that awakens faith and leads us to our destiny.
