To be revealed to Israel.
John 1:29-34 The next day he saw Jesus coming toward him, and said, “Behold, the Lamb of God, who takes away the sin of the world! This is he of whom I said, ‘After me comes a man who ranks before me, because he was before me.’ I myself did not know him, but for this purpose I came baptizing with water, that he might be revealed to Israel.” And John bore witness: “I saw the Spirit descend from heaven like a dove, and it remained on him. I myself did not know him, but he who sent me to baptize with water said to me, ‘He on whom you see the Spirit descend and remain, this is he who baptizes with the Holy Spirit.’ And I have seen and have borne witness that this is the Son of God.”
Matt 3:13Then cometh Jesus from Galilee to Jordan unto John, to be baptized of him .
Mat 3:14 But John forbad him, saying, I have need to be baptized of thee, and comest thou to me?
Mat 3:15 And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered him.
Mat 3:16 And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him:
The key verse is 15, particularly;
" ... for thus it becometh us to fulfil all righteousness"
Two people involved here ... John and Jesus and they both had a job to do.
John had to baptize and Jesus had to BE baptized ... simply ... in obedience.
The righteousness fulfilled is nothing more than being obedient.
Mat 3:17 And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.
PS ... Jesus saw the Spirir of God descending like a dove ... not John nor the crowd.
THIS was not the time to reveal Jesus ... that would come later.