John the Baptist was preaching in the wilderness, preparing the way for Our Lord. As John was baptizing the people in the Jordan River, Jesus came to be baptized Himself—not that He had sins to be forgiven, but to inaugurate His ministry. The voice of God the Father was heard to say, "This is My beloved Son, in Whom I am well-pleased," and the Holy Spirit appeared in the form of a dove. This was the great revelation of the Trinity as one God in three Persons.
The feast of Theophany (January 6) is closely connected to the feast of the Nativity of Christ, and in many ways it is celebrated as a single great festival, bridged by the Twelve Days of Christmas. In the Orthodox Church, Theophany is widely considered to be the greatest of the Twelve Great Feasts, and second only to Pascha in holiness.
This incredible Athonite fresco depicts the baptism scene. Christ stands in the water of the Jordan, where several creatures are visible, representing the deeps. The Angels stand on the shore, worshiping the Trinity, which is depicted with the Dove and a ray representing the Father's voice. The sea creatures represent the waters, after the Psalmist's words, "the sea saw and fled; the Jordan turned back."