Point 1: John’s imprisonment (19-20) 

¹⁹ But when John rebuked Herod the tetrarch because of his marriage to Herodias, his brother’s wife, and all the other evil things he had done, ²⁰ Herod added this to them all: He locked John up in prison.

·      This leads to mention of John’s beheading in Luke 9, but we read the full story of the prophet’s death in Mark 6 and Matthew 14.

Point 2: Jesus’ baptism (21-22)

²¹ When all the people were being baptized, Jesus was baptized too. And as he was praying, heaven was opened ²² and the Holy Spirit descended on him in bodily form like a dove. And a voice came from heaven: “You are my Son, whom I love; with you I am well pleased.”

·      The divine endorsement is marked by two elements: the divine word from heaven, and the anointing by the Spirit.  Together, these signs mark Jesus as the agent through whom God will work.

The three foundations of the Trinity

1.     Monotheism: there is only one God

2.     There are three divine persons: Father, Son, and Holy Spirit

3.     The persons are coequal and coeternal

The best-known example of the existence of three persons in the Godhead is the baptism of Jesus. Here the Father speaks from heaven, the Son is being baptized, and the Spirit is descending as a dove upon the Son. Jesus is not praying to himself, but to the Father, and he is spoken to by the Father.