The prophecy of Isaiah is about John the Baptist. “A voice cries out in the desert prepare the way of the LORD Make straight …the highway for our God.” This John spoken about is given the privilege to baptize our LORD. According to the account of Luke, “…Jesus also had been baptized and was praying. Heaven was opened and the Holy Spirit descended upon him in bodily form, like a dove. And a voice came from heaven, ‘You are my beloved Son and with you I am well pleased.’”
Few points for reflection:
The baptism of our Lord is spiritually significant in a number of ways. Through the Baptism of our LORD, all waters of baptism are thereby consecrated. His baptism is an act of great humility because he has no sin and did not need to be baptized. He is teaching us to appreciate the spiritual value of this sacrament. According to CCC 1224, “Our Lord voluntarily submitted himself to the baptism of St. John, intended for sinners, in order to ‘fulfill all righteousness,’ Mt 3:15 Jesus’ gesture is a manifestation of his self-emptying, Phil 2:7 The Spirit who had hovered the waters of the first creation descended then on the Christ as a prelude of the new creation, and the Father revealed Jesus as his beloved Son.” Mt 3:16-17
The Holy Spirit descended on Christ and filled him with divine gifts and power for his ministry. Human nature needs the Holy Spirit. You are my Son…, reveals the deep and intimate relationship between the Father and the Son. 
Beloved in Christ the Baptism of our Lord today should remind all of us of our own baptism. In baptism all our sins, original and personal sins are washed clean. We received the Holy Spirit who transformed us into children of God and members of the body of Christ, the Church. In baptism we died and rose with Christ to new life. 
After baptism Jesus was in prayer. An attitude of a baptized Christian, who has become the child of God, must be a life of prayer. Through constant prayer the reception of other Sacraments, the Body and Blood of Christ, the grace of Baptism is preserved and nurtured and nourished to become a strong Christian. Strong to remain faithful to the promises made at Baptism.
In this baptism account, we are told that the Holy Spirit descended on Christ like a dove. The Holy Spirit is always received during baptism. That is why our body is known as the temple of the Holy Spirit. So, for all of us who have been baptized, the Holy Spirit is dwelling in us. He fills us with divine grace, holiness, anointing and consecration. 
The Holy Spirit strengthens us in our spiritual struggle against sin/evil. The Holy Spirit gives us the divine wisdom to know and to do the holy will of God. He gives us the power to obey the word and commandments of God. He gives us the power to be faithful to our baptismal promises to reject sin, his works and empty show. 
Dear brothers and sisters, as we mark the baptism of our Lord, let us recommit/rededicate ourselves to God. Let us renew our commitment to our baptismal promises. Let us always allow the Spirit to lead us to pray. Let us allow the Spirit to strengthen us in the face of every temptation. He dwells in us to empower us, to fill us with faith, to comfort us in times of challenges and trials. He gives us hope even when we walk under the shadow Christ’s redeeming CROSS.