Matthew 3:6

Were baptized] The Baptism of John was specifically a baptism of repentance, of which public confession was the pledge and evidence. Its significance can be best described in the words of Isaiah: 'Wash you, make you clean; put away the evil of your doings from before mine eyes; cease to do evil; learn to do well; seek judgment' (justice), 'relieve the oppressed, judge the fatherless, plead for the widow' (Isaiah 1:16 cp. Zechariah 13:1). It has points of contact with the baptism of proselytes or converts from heathenism. John required circumcised Jews of the seed of Abraham to submit to his baptism, and thereby to declare themselves outside the Messianic kingdom, and unfit to enter into it without a moral purification. This was distasteful to the pride of the Pharisees, who took offence at being treated as proselytes (Luke 7:30). From John 1:26 it may be gathered that there was a general expectation that the Messiah and those closely associated with Him would baptise, so that John's action was in accordance with Jewish ideas. John's Baptism differed from that of Jesus in being of a preparatory character. It did not confer the Spirit, and was not recognised as equivalent to Christian baptism (Acts 18:25; Acts 19:3). Confessing their sins] The Gk. word generally, but not always, means a public confession, and that seems to be the sense here. For an example of public confession and repudiation of past sins in connexion with Christian baptism, see Acts 19:18.