...Bishops and Doctors
From: John 1:19-28
The Witness of John
 And this is the testimony of John, when the Jews sent priests and Levites from Jerusalem to ask him, "Who are you?"  He confessed, he did not deny, but confessed, "I am not the Christ."  And they asked him, "What then? Are you Elijah?" He said, "I am not." "Are you the prophet?" And he answered, "No."  They said to him then, "Who are you? Let us have an answer for those who sent us. What do you say about yourself?"  He said, "I am the voice of one crying in the wilderness, `Make straight the way of the Lord,' as the prophet Isaiah said."
 Now they had been sent from the Pharisees.  They asked him, "Then why are you baptizing, if you are neither the Christ, nor Elijah, nor the prophet?"  John answered, "I baptize with water; but among you stands One whom you do not know,  even He who comes after me, the thong of whose sandal I am not worthy to untie."  This took place in Bethany beyond the Jordan, where John was baptizing.
19-34. This passage forms a unity, beginning and ending with reference to the Baptist's "testimony": it thereby emphasizes the mission given him by God to bear witness, by his life and preaching, to Jesus as the Messiah and Son of God. The Precursor exhorts people to do penance and he practices the austerity he preaches; he points Jesus out as the Lamb of God who takes away the sin of the world; and he proclaims him boldly in the face of the Jewish authorities. He is an example to us of the fortitude with which we should confess Christ: "All Christians by the example of their lives and the witness of the word, wherever they live, have an obligation to manifest the new man which the put on in Baptism" (Vatican II, "Ad Gentes", 11).
19-24. In this setting of intense expectation of the imminent coming of the Messiah, the Baptist is a personality with enormous prestige, as is shown by the fact that the Jewish authorities send qualified people (priests and Levites from Jerusalem) to ask him if he is the Messiah.
John's great humility should be noted: he is quick to tell his questioners: "I am not the Christ". He sees himself as someone insignificant compared with our Lord: "I am not worthy to untie the thong of His sandal" (verse 27). He places all his prestige at the service of his mission as precursor of the Messiah and, leaving himself completely to one side, he asserts that "He must increase, but I must decrease" (John 3:30).
25-26. "Baptize": this originally meant to submerge in water, to bathe. For the Jews the rite of immersion meant legal purification of those who had contracted some impurity under the Law. Baptism was also used as a rite for the incorporation of Gentile proselytes into the Jewish people. In the Dead Sea Scrolls there is mention of a baptism as a rite of initiation and purification into the Jewish Qumran community, which existed in our Lord's time.
John's baptism laid marked stress on interior conversion. His words of exhortation and the person's humble recognition of his sins prepared people to receive Christ's grace: it was a very efficacious rite of penance, preparing the people for the coming of the Messiah, and it fulfilled the prophecies that spoke precisely of a cleansing by water prior to the coming of the Kingdom of God in the messianic times (cf. Zechariah 13:1; Ezekiel 36:25; 37-23; Jeremiah 4:14). John's baptism, however, had no power to cleanse the soul of sins, as Christian Baptism does (cf. Matthew 3:11; Mark 1:4).
"One whom you do not know": Jesus had not yet publicly revealed Him- self as Messiah and Son of God; although some people did know as a man, St. John the Baptist could assert that really they did not know Him.
27. The Baptist declares Christ's importance by comparing himself to a slave undoing the laces of his master's sandals. If we want to approach Christ, whom St. John heralds, we need to imitate the Baptist. As St. Augustine says: "He who imitates the humility of the Precursor will understand these words. [...] John's greatest merit, my brethren, is this act of humility" ("In Ioann. Evang.", 4, 7).
28. This is a reference to the town of Bethany which was situated on the eastern bank of the Jordan, across from Jericho--different from the Bethany where Lazarus and his family lived, near Jerusalem (cf. John 11:18).
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.