St. Matthew records: 'Then cometh Jesus from Galilee to the Jordan, unto John, to be baptized by him. And John stayed him, saying: I ought to be baptized by thee, and comest thou to me? And Jesus answering, said to him: Suffer it to be so now. For so it becometh us to fulfil all justice. Then he suffered him' (Mt 3:13–15). At the moment of His emergence from the water, three signs were given: the heavens were opened, the Holy Spirit descended visibly as a dove and rested upon Him, and the voice of the Father came from heaven (Mt 3:16–17).
This is the first public manifestation of the Most Holy Trinity in the New Testament — the Father speaking from heaven, the Son rising from the water, the Spirit descending as a dove. The site is identified by tradition (and by the Byzantine pilgrimage record) as Bethany Beyond the Jordan at the eastern shore of the river opposite Jericho. In 1996 the site was excavated; in 2015 it was designated a UNESCO World Heritage Site.
The Baptism inaugurates the public ministry of Christ. From this moment forward He proclaims the Kingdom, gathers the Twelve, and works His signs. Many Fathers of the Church (Sts. Ambrose, Augustine, Cyril of Jerusalem) saw in the Lord's Baptism the sanctification of the waters and the foundation of the Christian sacrament of Baptism.