Theophany of our Lord
On January 6th we remember Christ's baptism by John the Forerunner in the River Jordan, and the beginning of Christ's earthly ministry. The Feast of Theophany is the culmination of the Christmas Season. In mystic commemoration of this event, the Great Blessing of Water is performed on this day, and the holy water so blessed is used by the local priest to bless the homes of the faithful.
We call this feast Theophany because during Christ's baptism the Holy Trinity was clearly communicated to mankind for the first time -- the Father's voice is heard from Heaven, the Son of God is incarnate and standing physically in the Jordan, and the Holy Spirit descends on Him in the form of a dove.
Troparion of the Feast
Source: OrthodoxWiki. This article is released under the GNU Free Documentation License.