At his baptism, Jesus provides a pattern for all who seek to follow him. Water baptism is the most primal of the sacraments. Drawing from the first creation account, it communicates a new creation in play. Genesis 1:1 describes an initial earth, formless and empty, with darkness over the surface of the deep, and the Spirit of God was hovering over the waters. And God said, “Let there be light” and so forth.
Our life begins in water and slides out into this noisy world very wet. Newborns are approximately 75% water. In the OT, water is the image of both chaos and life; Jesus uses water to describe being born from above, speaking to Nicodemus. Referring to baptism, Jesus tells Nicodemus that no one can enter the kingdom of God unless they are born of water and the Spirit. Jesus is drawing from the first creation story.
He’s saying that plunging into the waters effects union with him in his death and coming up out of the waters effects union with him in his resurrection. Those who obey the command to be baptized, through faith and grace, come into union with Christ in his death and resurrection. This is how we come to be “in Christ.”
Thus, baptism is entering a new life, being grafted into Christ, being joined in his new creation. Water and Spirit is the doorway into the Kingdom of God, says Jesus. Baptism is the means of dying to one’s old humanity and rising in newness of life, joined to Christ in His new humanity, whereby we are united to the Holy Trinity.
Far from being a mere symbolic ritual, baptism is a sacrament, a mysterious means of receiving God’s grace; for, on the day of Pentecost, Peter answers the question of the on-looking masses, “What must we do to be saved?” He answers, “Repent and be baptized for the forgiveness of your sins. And you will receive the Holy Spirit. The promise is for you and your children and for all who are far off—for all whom the Lord our God will call.” Acts 2:38-39