Historically Theophany was even a more important feast than the Nativity (and in fact was celebrated in the Orthodox Church much before Nativity). Theophany is considered by the gospels as a turning point in salvation history because, as the Orthodox Theophany hymn states: "When Thou, O Lord, wast baptized in the Jordan, the worship of the Trinity was made manifest. The voice of the Father bore witness to Thee, calling Thee His beloved Son. And the Spirit in the form of a dove confirmed the truthfulness of His word…." While the Trinitarian dimensions of our faith are revealed at Christ's baptism, we also see the totality Christ's identification with fallen man (and indeed the whole of fallen creation) through His baptism and the subsequent sanctification and 're-creation' effected by it.
Baptism is the symbol of death and resurrection; Christ came to the earth in order to die and be raised. Baptism is a symbol of repentance of sin and its forgiveness; Christ came as the Lamb of God who takes upon Himself the sin of the world in order to take it away. Baptism is a symbol of sanctification; Christ has come to sanctify the whole of creation. Baptism is a symbol, finally, of radical renewal. When one is baptized the old is over and the new has come. And Christ has appeared on earth to bring all things to an end, and to make all things new. The act of baptism, therefore, contains in symbol the entire mystery of Christ, the whole purpose of his coming.
For this reason, baptism necessarily involves water, the 'primordial element,' upon which all life depends, and which plays such a pivotal role in the creation itself and in the salvation of God's people throughout the Old Testament. The original creation itself began with water.
And God said, "Let there be a firmament in the midst of the waters, and let it separate the waters from the waters." And God made the firmament and separated the waters which were under the firmament from the waters which were above the firmament. And it was so. And God called the firmament Heaven. And there was evening and there was morning, a second day. And God said, "Let the waters under the heavens be gathered together into one place, and let the dry land appear." And it was so. God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good.
Water was also the means of salvation for the Israelites, as God through Moses saved the ancient Jews from their bondage in Egypt, saving them from the Egyptians by drowning them in the Red Sea.
So Moses stretched forth his hand over the sea, and the sea returned to its wonted flow when the morning appeared; and the Egyptians fled into it, and the LORD routed the Egyptians in the midst of the sea. The waters returned and covered the chariots and the horsemen and all the host of Pharaoh that had followed them into the sea; not so much as one of them remained. But the people of Israel walked on dry ground through the sea, the waters being a wall to them on their right hand and on their left. Thus the LORD saved Israel that day from the hand of the Egyptians; and Israel saw the Egyptians dead upon the seashore.
Also, as the ancient Jews wandered in the desert thirsting for water, the Lord said to Moses: "Behold, I will stand there before thee, upon the rock in Horeb; and thou shalt strike the rock and water shall come out of it, that the people may drink".
These two events are mentioned in I Cor. 10:1ff as manifestations of Christ. The rock WAS Christ, St Paul insists, and not merely representative. This foreshadows the sacramental nature of water and its relationship to salvation. Water also played an important role within the Law of Moses, signifying holiness, cleansing, renewal and the return to a right relationship with God and man. There are multitudes of passages on ritual cleansing, but the prayer of David sums them all up: "Have mercy on me, O God, according to thy steadfast love; according to thy abundant mercy blot out my transgressions. Wash me thoroughly from my iniquity, and cleanse me from my sin" (Ps 51: 1, 2)!
The Festal Matins of Theophany sums it up quite well: "By [Christ's] descending into water we ascend to God". Thus, at Theophany, we see the GREAT MYSTERY of the Incarnation which was celebrated at Christ's Nativity moving toward its fulfillment in the Cross and Resurrection: Jesus Christ, God incarnate, having taken a material body, descends into the water of the Jordan in order that we may ascend to God. God becomes flesh that we might become temples of the Spirit once again. The material creation in Christ IS the means for our salvation. We are saved BY AND THROUGH THE MATERIAL BODY OF CHRIST. In descending into water, Christ sanctified water and Christ's union with humanity and our union with His divinity is revealed through the material creation. Thus the entire cosmos is proclaimed to be God's Temple, and all of creation as having the power to bring union between God and man, or as St. Gregory of Nyssa stated in The Great Catechism "…it is the property of the Godhead to pervade all things and to extend Itself through the length and breadth of the essence of existence in every part".
God thus uses creation (the dust of the earth) to create us, and breathes His Spirit into us. The human being is not created "ex nihilo" like all the rest of creation, but out of what is existing. We bear the totality of God's image: spirit-bearing matter. The human being is called the "microcosm" of creation by the Fathers. Man was to be the "bridge" between the creation and the spiritual world because it was only man that had elements of both. Romans 8 speaks of the connection between the human being and creation's salvation and redemption from corruption. Man failed in that "job", so Christ, in His flesh, united divinity and the creation again opening the door for the human being and ALL THE COSMOS to be brought together, or as St. Paul says "summed up in Christ" (Eph. 1:3,10, Col. 15-20).
This 'materiality' of salvation was even prefigured from the beginning. The Garden of Eden was a created place, after all. It had two trees: one brought knowledge of good and evil, and the other was the Tree of Life (which itself is a prefiguration of the Tree of the Cross). When Adam and Eve sinned an angel was put to guard the Tree of Life lest they eat and live forever. A MATERIAL TREE BROUGHT PHYSICAL ETERNAL LIFE. So, just as God used creation to create us, just as He guarded creation to keep us from living eternally in our fallen created states, He now uses creation to re-create us in the waters of baptism.
From Genesis 1 to Revelation 22, the scripture begins with water and ends with water. By blessing and uniting Himself to the waters of creation, God restores water to its original purposes in Christ. Thus the waters of baptism are a real union with Christ's death and resurrection, sin is really destroyed by a material means, and water, by the power of God in the Holy Spirit, becomes the agent of eternal life, just as the Tree of Life in the Garden of Eden would have imparted eternal physical life. The sacramental nature of our life in Christ is seen in the water of baptism, and by extension in the blessed waters of Theophany. The sacrament is the acknowledgment of the water and the blood, the physical body of Christ being joined to water and the Spirit. Christ's physical body is the cause and means of our salvation. Matter IS spiritual; it is the agent of creation and re-creation. In and through Christ's baptism in the River Jordan, the nature of the waters is 'changed': the whole of creation is re-created, and man's salvation is revealed. Or as St John Chrysostom states: "But we know that the water did not cleanse Him, the most holy and sinless One; but it was He who sanctified the water by deigning to be washed by it, as was sung today during the sanctification of the water: "Today the nature of the waters is sanctified."