Matthew 3:1-12: "1 In those days John the Baptist came preaching in the wilderness of Judea, 2 'Repent, for the kingdom of heaven is at hand.' 3 For this is he who was spoken of by the prophet Isaiah when he said, 'The voice of one crying in the wilderness: "Prepare the way of the Lord; make his paths straight."' 4 Now John wore a garment of camel's hair and a leather belt around his waist, and his food was locusts and wild honey. 5 Then Jerusalem and all Judea and all the region about the Jordan were going out to him, 6 and they were baptized by him in the river Jordan, confessing their sins.
"7 But when he saw many of the Pharisees and Sadducees coming to his baptism, he said to them, 'You brood of vipers! Who warned you to flee from the wrath to come? 8 Bear fruit in keeping with repentance. 9 And do not presume to say to yourselves, "We have Abraham as our father," for I tell you, God is able from these stones to raise up children for Abraham. 10 Even now the axe is laid to the root of the trees. Every tree therefore that does not bear good fruit is cut down and thrown into the fire.
"11 'I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire. 12 His winnowing fork is in his hand, and he will clear his threshing floor and gather his wheat into the barn, but the chaff he will burn with unquenchable fire.'"
Luke 2:8-14: "8 And in the same region there were shepherds out in the field, keeping watch over their flock by night. 9 And an angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were filled with fear. 10 And the angel said to them, 'Fear not, for behold, I bring you good news of great joy that will be for all the people. 11 For unto you is born this day in the city of David a Savior, who is Christ the Lord. 12 And this will be a sign for you: you will find a baby wrapped in swaddling cloths and lying in a manger.' 13 And suddenly there was with the angels a multitude of the heavenly host praising God and saying, 14 'Glory to God in the highest, and on earth peace among those with whom he is pleased!'"
John 1:29-34: "29 The next day he saw Jesus coming toward him, and said, 'Behold, the Lamb of God, who takes away the sin of the world! 30 This is he of whom I said, "After me comes a man who ranks before me, because he was before me." 31 I myself did not know him, but for this purpose I came baptizing with water, that he might be revealed to Israel.' 32 And John bore witness: 'I saw the Spirit descend from heaven like a dove, and it remained on him. 33 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." 34 And I have seen and have borne witness that this is the Son of God.'"
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The first two verses come from the text from Matthew. The first verse, specifically "Warning us of right and wrong, / Turning us from sin and sadness," comes from verses 1-2, and the second, specifically "Make a pathway through the desert / For the one who brings God near," from verse 3 (cited from Isaiah 40:3).
The third verse, in which the herald is exhorted to "sound the note of pardon," comes from the text from John, in which John exclaims that Jesus "takes away the sin of the world."
The fourth verse, specifically the line "Christ has come to share our life" - and perhaps even the line "Christ, the Savior king, is come!" in the refrain - comes from the text from Luke, which details Jesus' birth.
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The line "Granting vict'ry in our strife" in the fourth verse might come from 1 Corinthians 15:57: "But thanks be to God, who gives us the victory through our Lord Jesus Christ."
Each verse begins with a call to a herald to sound various notes: "Herald, sound the note of judgement," "Herald, sound the note of gladness," "Herald, sound the note of pardon," and "Herald, sound the note of triumph." This repetition is a rhetorical effect called anaphora.
