Luke 2:1-14: "1 In those days a decree went out from Caesar Augustus that all the world should be registered. 2 This was the first registration when Quirinius was governor of Syria. 3 And all went to be registered, each to his own town. 4 And Joseph also went up from Galilee, from the town of Nazareth, to Judea, to the city of David, which is called Bethlehem, because he was of the house and lineage of David, 5 to be registered with Mary, his betrothed, who was with child. 6 And while they were there, the time came for her to give birth. 7 And she gave birth to her firstborn son and wrapped him in swaddling cloths and laid him in a manger, because there was no place for them in the inn.
"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 12:32: "'And I, when I am lifted up from the earth, will draw all people to myself.'"
1 Peter 1:8-9: "8 Though you have not seen him, you love him. Though you do not now see him, you believe in him and rejoice with joy that is inexpressible and filled with glory, 9 obtaining the outcome of your faith, the salvation of your souls."
Revelation 21:3-4: "3 And I heard a loud voice from the throne saying, 'Behold, the dwelling place of God is with man. He will dwell with them, and they will be his people, and God himself will be with them as their God. 4 He will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning, nor crying, nor pain anymore, for the former things have passed away.'"
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The text is public domain:
Now sing we, now rejoice,
Now raise to heav'n our voice;
He from whom joy streamth
Poor in a manger lies;
Not so brightly beameth
The sun in yonder skies.
Thou my Savior art!
Thou my Savior art!
Come from on high to me;
I cannot rise to Thee.
Cheer my wearing spirit,
O pure and holy Child;
Through Thy grace and merit,
Blest Jesus, Lord most mild,
Draw me unto Thee!
Draw me unto Thee!
Now through His Son doth shine
The Father's grace divine.
Death was reigning o'er us
Through sin and vanity
Till He opened for us
A bright eternity.
May we praise Him there!
May we praise Him there!
Oh, where shall joy be found?
Where but on heav'nly ground?
Where the angels singing
With all His saints unite,
Sweetest praises bringing
In heav'nly joy and light.
Oh, that we were there!
Oh, that we were there!
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The title line ("Now sing we, now rejoice") seems to come from 1 Peter, specifically "you believe in him and rejoice with joy that is inexpressible and filled with glory." The lines "Poor in a manger lies" in the first verse and "O pure and holy Child" in the second come from the Luke text.
The Revelation text appears in the third verse. Revelation 21:4 says that "the former things have passed away." In the hymn, this is rendered as "Death was reigning o'er us / Through sin and vanity / Till He opened for us / A bright eternity."
John 12:32 seems to be referred to in the last two verses. Jesus says that He will "draw all people" to Him, and the hymn portrays this as "prais[ing] Him there [in heaven]... in heav'nly joy and light."
