This is the testimony of John.
When the Jews from Jerusalem sent priests and Levites to him
to ask him, “Who are you?”
He admitted and did not deny it, but admitted,
“I am not the Christ.”
So they asked him,
“What are you then? Are you Elijah?”
And he said, “I am not.”
“Are you the Prophet?”
He answered, “No.”
So they said to him,
“Who are you, so we can give an answer to those who sent us?
What do you have to say for yourself?”
“I am the voice of one crying out in the desert,
‘Make straight the way of the Lord,’
as Isaiah the prophet said.”
Some Pharisees were also sent.
They asked him,
“Why then do you baptize
if you are not the Christ or Elijah or the Prophet?”
John answered them,
“I baptize with water;
but there is one among you whom you do not recognize,
the one who is coming after me,
whose sandal strap I am not worthy to untie.”
This happened in Bethany across the Jordan,
where John was baptizing.
1:19 The Jews: throughout most of the gospel, the “Jews” does not refer to the Jewish people as such but to the hostile authorities, both Pharisees and Sadducees, particularly in Jerusalem, who refuse to believe in Jesus. The usage reflects the atmosphere, at the end of the first century, of polemics between church and synagogue, or possibly it refers to Jews as representative of a hostile world (Jn 1:10–11).
1:20 Messiah: the anointed agent of Yahweh, usually considered to be of Davidic descent. See further the note on Jn 1:41.
1:21 Elijah: the Baptist did not claim to be Elijah returned to earth (cf. Mal 3:19; Mt 11:14). The Prophet: probably the prophet like Moses (Dt 18:15; cf. Acts 3:22).
1:23 This is a repunctuation and reinterpretation (as in the synoptic gospels and Septuagint) of the Hebrew text of Is 40:3 which reads, “A voice cries out: In the desert prepare the way of the Lord.”
1:24 Some Pharisees: other translations, such as “Now they had been sent from the Pharisees,” misunderstand the grammatical construction. This is a different group from that in Jn 1:19; the priests and Levites would have been Sadducees, not Pharisees.
1:26 I baptize with water: the synoptics add “but he will baptize you with the holy Spirit” (Mk 1:8) or “… holy Spirit and fire” (Mt 3:11; Lk 3:16). John’s emphasis is on purification and preparation for a better baptism.
1:28 Bethany across the Jordan: site unknown. Another reading is “Bethabara.”
“I am the voice of one crying out in the desert”
In today’s Gospel, John the Baptist identifies himself as “the voice of one crying out in the desert.” How often the great heroes of the Biblical revelation have to spend time in the desert: Abraham, Moses, John the Baptist, Paul. Even Jesus himself spends forty days and nights in the desert before commencing his ministry.
They have to wait through a painful time, living a stripped-down life, before they are ready. What does the desert symbolize? Confrontation with one’s own sin; seeing one’s dark side; a deep realization of one’s dependency upon God; an ordering of the priorities of one’s life; a simplification, a getting back to basics. It means any and all of these things.
But the bottom line is that they are compelled to wait, during a time and in a place where very little life seems to be on offer. But it is precisely in such deserts that the flowers bloom. Moses becomes a great leader; Abraham is the father of many nations; Joseph becomes the savior of his people; John the Baptist is the forerunner of the Messiah; Paul is the apostle to the Gentiles—all of this flowering was made possible by the desert.
– Bishop Robert Barron
May the virtues of faith, hope, and love go with you today – DV.
 Donald Senior, John J. Collins, and Mary Ann Getty, eds., The Catholic Study Bible, 2nd Ed.: Notes, 2nd ed., vol. 2 (New York: Oxford University Press, 2011), 1488–1489.