Read Luke 3:21-22

THE BAPTISM OF JESUS
Luke emphasizes Jesus’ human nature. Jesus was born to humble parents, a birth unannounced except to shepherds and foreigners. This baptism recorded here was the first public declaration of Jesus’ ministry. Instead of going to Jerusalem and identifying with the established religious leaders, Jesus went to a river and identified Himself with those who were repenting of sin. When Jesus, at age 12, visited the Temple, He understood His mission. Eighteen years later, at His baptism, He began carrying it out. And as Jesus prayed, God confirmed His decision to act. God was breaking into human history through Jesus Christ.
If baptism was a sign of repentance from sin, why did Jesus ask to be baptized? Several explanations have been given: 1) Jesus’ baptism was one step in fulfilling His earthly mission of identifying with our humanity and sin; 2) by endorsing the rite of baptism, Jesus was giving us an example to follow; 3) Jesus was announcing the beginning of His public ministry: 4) Jesus was being baptized for the sins of the nation.
The Holy Spirit’s appearance in the form of a dove showed that God’s plan for Salvation was centered in Jesus. He was the perfect human who didn’t need baptism for repentance, but He was baptized anyway on our behalf.
This is one of several places in Scripture where all the members of the Trinity are mentioned – God the Father, Son, and Holy Spirit. In the traditional words of the church, the one God exists in three persons but one substance, co-eternal and co-equal. No amount of explanation can adequately portray the power and intricacy of this unique relationship. There are no perfect analogies in nature because there is no other relationship like the Trinity.