O Lord Jesus Christ, the Only-begotten Son, who being in the bosom of the Father, True God, source of life and immortality, Light of Light, who came into the world to enlighten it, shine upon our understanding with Your Holy Spirit and accept us who offer unto You glory and thanksgiving for all Your great and wondrous works from all ages, and for Your saving dispensation in these last times.
For you have clothed Yourself in our poor and feeble nature, and have submitted Yourself to servitude, You who are King of all; and submitted Yourself to servitude, You who are King of all; and moreover You surrendered to being baptized in the Jordan by the hand of a servant, that having sanctified the nature of the waters, O sinless Lord, You might lead us to a new birth through water and Spirit, and restore us again to our original freedom.
As we keep this feast in remembrance of this divine mystery, we beg You, O Master who loves mankind: sprinkle upon us, Your unworthy servants, according to your divine promise, cleansing water, the gift of Your compassion; grant unto us and to all Your faithful people the glory of Your holy and venerated Name.
For unto You, together with the Father who is without beginning, and Your most holy, good, and life-giving Spirit, are due all glory, honor, and worship, now and forever, and unto the age of ages. Amen.
from The Feast of the Theophany
The Festal Menaion, Orthodox liturgical book of feasts. freely modified
When all the people were being baptized, Jesus was baptized too. And as he was praying, heaven was opened and the Holy Spirit descended on him in bodily form like a dove. And a voice came from heaven: “You are my Son, whom I love; with you I am well pleased.”