On January 6, the Feast of the Holy Epiphany is celebrated by the Orthodox Church. It is the commemoration of the Baptism of Jesus Christ in the River Jordan by John the Baptist, and the divine revelation of the Holy Trinity.
At the Baptism of Christ, all three Persons of the Holy Trinity — Father, Son, and Holy Spirit — were made manifest. Thus, the name of the Feast is “Epiphany”, meaning manifestation, or “Theophany”, meaning manifestation of God.
John the Baptist, the cousin of Jesus and the one chosen by God to proclaim His coming, was preaching in the wilderness and was baptizing all who would respond to his message calling for repentance. As he was doing this, John was directing the people toward the one who would baptize them with the Holy Spirit (Matthew 3:11).
The Scriptures tell us that Jesus came from Galilee to John at the Jordan to be baptized by him. Initially, not feeling worthy of baptizing The Son Of God, John told Jesus that Jesus should baptize him. Jesus said to John, “Let it be so now; for it is proper for us in this way to fulfill all righteousness” (3:15). John consented and baptized Jesus.
When Jesus came up from the water, the heavens opened, and The Holy Spirit descended upon Him. The Bible records that the Spirit descended like a dove and alighted on him. When this happened, a voice came from heaven and said, “This is my Son, the Beloved, with whom I am well pleased”. This was the voice of God the Father.
Check out the following sites to find out more info about The Feast of the Holy Epiphany:
https://greekcitytimes.com/2020/01/06/the-feast-of-the-holy-epiphany/
https://en.wikipedia.org/wiki/Epiphany_(holiday)