John 13:1-17: "1 Now before the Feast of the Passover, when Jesus knew that his hour had come to depart out of this world to the Father, having loved his own who were in the world, he loved them to the end. 2 During supper, when the devil had already put it into the heart of Judas Iscariot, Simon's son, to betray him, 3 Jesus, knowing that the Father had given all things into his hands, and that he had come from God and was going back to God, 4 rose from supper. He laid aside his outer garments, and taking a towel, tied it around his waist. 5 Then he poured water into a basin and began to wash the disciples' feet and to wipe them with the towel that was wrapped around him. 6 He came to Simon Peter, who said to him, 'Lord, do you wash my feet?' 7 Jesus answered him, 'What I am doing you do not understand now, but afterward you will understand.' 8 Peter said to him, 'You shall never wash my feet.' Jesus answered him, 'If I do not wash you, you have no share with me.' 9 Simon Peter said to him, 'Lord, not my feet only but also my hands and my head!' 10 Jesus said to him, 'The one who has bathed does not need to wash, except for his feet, but is completely clean. And you are clean, but not every one of you.' 11 For he knew who was to betray him; that was why he said, 'Not all of you are clean.'
"12 When he had washed their feet and put on his outer garments and resumed his place, he said to them, 'Do you understand what I have done to you? 13 You call me Teacher and Lord, and you are right, for so I am. 14 If I then, your Lord and Teacher, have washed your feet, you also ought to wash one another's feet. 15 For I have given you an example, that you also should do just as I have done to you. 16 Truly, truly, I say to you, a servant is not greater than his master, nor is a messenger greater than the one who sent him. 17 If you know these things, blessed are you if you do them.'"
1 John 4:7-21: "7 Beloved, let us love one another, for love is from God, and whoever loves has been born of God and knows God. 8 Anyone who does not love does not know God, because God is love. 9 In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him. 10 In this is love, not that we have loved God but that he loved us and sent his Son to be the propitiation for our sins. 11 Beloved, if God so loved us, we also ought to love one another. 12 No one has ever seen God; if we love one another, God abides in us and his love is perfected in us.
"13 By this we know that we abide in him and he in us, because he has given us of his Spirit. 14 And we have seen and testify that the Father has sent his Son to be the Savior of the world. 15 Whoever confesses that Jesus is the Son of God, God abides in him, and he in God. 16 So we have come to know and to believe the love that God has for us. God is love, and whoever abides in love abides in God, and God abides in him. 17 By this is love perfected with us, so that we may have confidence for the day of judgement, because as he is so also are we in this world. 18 There is no fear in love, but perfect love casts out fear. For fear has to do with punishment, and whoever fears has not been perfected in love. 19 We love because he first loved us. 20 If anyone says, 'I love God,' and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen. 21 And this commandment we have from him: whoever loves God must also love his brother."
Ephesians 4:29-32: "29 Let no corrupting talk come out of your mouths, but only such as is good for building up, as fits the occasion, that it may give grace to those who hear. 30 And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption. 31 Let all bitterness and wrath and anger and clamor and slander be put away from you, along with all malice. 32 Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you.
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The passage from John 13 seems to be what's alluded to in the lines "With grateful joy and holy fear / His charity we learn."
Part of 1 John 4:12 is paraphrased in the hymn's first two lines: "Where charity and love prevail / There God is ever found." 1 John 4:11 and 21 are the basis for the line "And let us love each other well" in the third verse. This is the same general idea as "'you also ought to wash one another's feet'" from John 13:14 and "forgiving one another" from Ephesians 4:32. 1 John 4:21 is also the basis for the sixth verse: "For love excludes no race or clan / That names the Savior's name; / His family embraces all / Whose Father is the same."
Ephesians 4:29 and 31 are echoed in the lines "Let strife among us be unknown; / Let all contention cease" at the beginning of the fourth verse. "Forgiving one another" from verse 32 appears in the lines "Forgive we now each other's faults / As we our faults confess" at the beginning of the third verse, although the structure in the hymn text is closer to Luke 11:4: "'and forgive us our sins, for we ourselves forgive everyone who is indebted to us. And lead us not into temptation.'"
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The lines "As members of His body joined / We are in Him made one" at the end of the fifth verse use the same imagery as Romans 12:5 ("so we, though many, are one body in Christ, and individually members one of another") and Ephesians 4:15-16 ("15 Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ, 16 from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love.").
