(Source) In the Orthodox Church it is customary, on the day following the Great Feasts of the Lord and the Mother of God, to remember those saints who participated directly in the sacred event. So, on the day following the Theophany of the Lord, the Church honors the one who participated directly in the Baptism of Christ, placing his own hand upon the head of the Savior.
St John, the holy Forerunner and Baptist of the Lord, whom the Lord called the greatest of the prophets, concludes the history of the Old Testament and opens the era of the New Testament. The holy Prophet John bore witness to the Only-Begotten Son of God, incarnate in the flesh. St John was accounted worthy to baptize Him in the waters of the Jordan, and he was a witness of the Theophany of the Most Holy Trinity on the day of the Savior’s Baptism.
The holy Prophet John was related to the Lord on His mother’s side, the son of the Priest Zachariah and Righteous Elizabeth. The holy Forerunner, John, was born six months before Christ. The Archangel Gabriel announced his birth in the Temple at Jerusalem, revealing to Zachariah that a son was to be born to him.
Through the prayers offered beforehand, the child was filled with the Holy Spirit. St John prepared himself in the wilds of the desert for his great service by a strict life, by fasting, prayer and sympathy for the fate of God’s people.
At the age of thirty, he came forth preaching repentance. He appeared on the banks of the Jordan, to prepare the people by his preaching to accept the Savior of the world. In church hymnology, St John is called a “bright morning star,” whose gleaming outshone the brilliance of all the other stars, announcing the coming dawn of the day of grace, illumined with the light of the spiritual Sun, our Lord Jesus Christ.
Having baptized the sinless Lamb of God, St John soon died a martyr’s death, beheaded by the sword on orders of King Herod at the request of his daughter Salome. (On St John the Baptist, see Mt.3:1-16, 11:1-19, 14:1-12; Mark 1:2-8, 6:14-29; Luke 1:5-25, 39-80, 3:1-20, 7:18-35, 9:7-9; John 1:19-34, 3:22-26).