Here we see the Blessed Trinity come during Baptism. Baptism is an important Sacrament. It removes Original Sin and leaves an indelible mark on our souls showing we belong to God - Father, Son, Holy Spirit. Just like we are all born of water in the womb; our souls are born in water with the words, "I Baptize you in the Name of the Father, Son and Holy Spirit."
Jesus in getting baptized shows that He is one of us. He is human, but without sin. He is human, but also God. He came to lead us by example.
Let us meditate on this great Sacrament and encourage those we know who are not baptized or have children who are not baptized to go and receive this Sacrament.