These notes are taken primarily from Catholic sources. I’ve added some thoughts of my own. I’ve mentioned on several occasions that their are connections between this passage and the theme of opposition from Satan and the world but have not developed them.
Joh 13:31 When he therefore was gone out, Jesus said: Now is the Son of man glorified; and God is glorified in him.
The he mentioned here is, of course, Judas, his departure to betray Jesus sets in motion the hour. This section of the Gospel, which began in 13:1 began with the words: “Now before the feast of the passover, Jesus knowing that his hour was come that he should depart out of this world unto his Father, having loved his own that were in the world, he loved them unto the end” (ASV). Everything that came between these two verses has prepared for this announcement: Now is the Son of Man glorified…” See verse -3, 10-11. Thus is introduced into the Passion Narrative a theme which has dominated the Gospel, the clash of the designs of God and the designs of Satan (Fr. Francis J. Moloney, The Gospel Of John, pg. 374). See 8:39-47; 15:18-16:4.
When he therefore was gone out Jesus said. “The departure of Judas marked the beginning of the end, and Jesus at once turned to the eleven with words that prove His knowledge of what was about to happen, and His acceptance of the issue of the traitor’s work (Nolan and Brown).
Now is the son of man glorified. Judas had finally decided to betray Him, and He Himself had fully accepted what was to follow, so that His death, now so certain and so near, might be spoken of a already past: “is…glorified.” For their consolation and encouragement He refers to His death as a glorification, as indeed it was, being a triumph over Satan and sin, and the prelude to victory over death. (Nolan and Brown).
Glorified. Frank L. Couch, Dean and Vice President of The Moravian Theological Seminary gives a pretty good summary of the meaning of Glory in the fourth Gospel: One cannot preach on the glory mentioned in verses 31-32 without setting it in the context of the whole of John. The meaning emerges within the narrative. The glory is inherent in the Son, something he had in God’s presence before the world was made (17:5) and that he brings with him into the world (1:14). Those who are his can see that glory, the ultimate outward sign of inward grace and truth (1:14-18). At the same time, it is inherent in him, however, it does not reach its fullness until he has completed the work his Father sent him to do (7:39; 17:4). Thus, although his glory is revealed to the disciples at Cana (2:11), promised to be shown again following the illness of Lazarus (11:4), and promised again to Martha at Lazarus’ tomb (11:40), in a real sense, only with the arrest, crucifixion, and death does the hour finally come for him to be glorified (12:23; 17:1). [Emphasis mine. For more on this important point of Johannine theology consult the essay “Johannine Theology 80:30-34, by Fr. Bruce Vawter in The Jerome Biblical Commentary; Also, The Introduction to the commentary on John by Fr. Dom Ralph Russell, in The New Catholic Commentary On Holy Scripture, 798:f-g;)
Joh 13:32 If God be glorified in him, God also will glorify him in himself: and immediately will he glorify him.
The Catholic Commentary On Holy Scripture: “Since he is to glorify God by his Passion, God will glorify him; ‘in himself’ may refer to the glorified or to the glorifier. The resurrection and ascension, forming a unity with the Passion, are regarded as immediately imminent.” (Note: This work should not be confused with The New Catholic Commentary mentioned above. That work is a total revision of this earlier one).
Here is how St Thomas Aquinas understood the passage: “Now the merit of this glorification is that God would be glorified in him. For God is glorified by those who seek to do his will, and not their own. Christ was like this: “For I have come down from heaven not to do my own will, but the will of him who sent me” (6:38). And this is why in him God is glorified. He amplifies on this when he says, if God is glorified in him, that is, if, by doing the will of God, he glorifies God, then rightly God will also glorify him in himself, so that the human nature assumed by the eternal Word will be given an eternal glory. Thus, in himself, that is, in his own glory: “Therefore God has highly exalted him and bestowed on him the name which is above every name” (Phil 2:9). Therefore the glorification by which God is glorified in Christ is the merit in virtue of which Christ as man is glorified in himself, that is, in the glory of God. This will occur when his human nature, its weakness having been laid down by the death of the cross, receives the glory of immortality at the resurrection. So the resurrection itself was the source from which this glory began. Accordingly he says, and will glorify him at once, at the resurrection, which will quickly come: “I will arise in the morning early” [Ps 108:2]: and also, “You will not let your Holy One see corruption” [Ps 16:10].” (source, scroll down to lecture 6, art. 1828)
Joh 13:33 Little children, yet a little while I am with you. You shall seek me. And as I said to the Jews: Whither I go you cannot come; so I say to you now.
Jesus addresses his apostles with the tender diminutive “little children,” used only here in John’s Gospel but 8 times in the First Epistle. Of special note is it usage in 1 Jn 4, where it is used in the context of opposition from the Antichrist and the world. Jesus had on several occasions warned the unbelievers among his people that a time would come when they would seek but not find him:
Joh 7:33 Jesus therefore said to them: Yet a little while I am with you: and then I go to him that sent me.
Joh 7:34 You shall seek me and shall not find me: and where I am, thither you cannot come.
Joh 8:21 Again therefore Jesus said to them: I go: and you shall seek me. And you shall die in your sin. Whither I go, you cannot come.
Joh 12:35 Jesus therefore said to them: Yet a little while, the light is among you. Walk whilst you have the light, and the darkness overtake you not. And he that walketh in darkness knoweth not whither be goeth.
Joh 12:36 Whilst you have the light, believe in the light, that you may be the children of light. These things Jesus spoke: and he went away and hid himself from them.
Jesus words to the unbelievers and to the disciples is not identical in meaning, providing a contrast; thus Nolan and Brown: “The glorification of Christ implied His departure from the Apostles, and the time was now come for making known to them the separation. at present they, any more than His enemies, could not follow Him, and what He had before declared to His enemies, He now declares to His dearest friends. Yet, though the substance of the declaration is in both cases the same, Christ’s purpose in making it was very different. To the Jews ti was made in hope that they would thus be urged to make good use of the time that still remained to them before the separation, while in the present case the motive seems rather to forearm the apostles by forewarning them and putting before them various motives of consolation. Little children you shall seek me &c. The declaration is somewhat different in form on this second occasion. The words: “And shall not find me” (7:34) are omitted, and instead of : “where I am” the present text has: “wither I go.” As we have said, the leading idea is both cases is of separation, but since that separation was to be followed in the case of the Apostles by spiritual union (14:18, 23), He now omits the words “and shall not find me;” though in the sense of not finding Him any longer visibly present among them…”
Those who remain in opposition to the person, work, and word of Jesus can never find Him. Once again the clash between the designs of God and those of Satan/the world come into play.
Joh 13:34 A new commandment I give unto you: That you love one another, as I have loved you, that you also love one another.
Jesus, “having loved his own who were in the world, he loved them unto the end” (vs 1) symbolized His love unto death by the footwashing, bidding his disciples to serve one another in like manner. The same idea will become more explicit in 15:12-14~
Joh 15:12 This is my commandment, that you love one another, as I have loved you.
Joh 15:13 Greater love than this no man hath, that a man lay down his life for his friends.
Joh 15:14 You are my friends, if you do the things that I command you.
Father MacIntyre: A new commandment…that you love on another as I have loved you. καθως ηγαπησα (Just as I have loved). the aorist is used because our Lord is speaking as it were historically, considering Himself as already at the end of His work (vss 1, 31). Our Lord, then, about to leave the Apostles, gives them instruction for their guidnace; and first ‘a new commandment.’ But in what sense new? for the command itself of love was very old (Lev 19:18). Two very different Greek adjectives are translated ‘new’ in the English Testament: the one is νέος (neos), denoting the ‘new’ primarily in reference to time (=recent, young, see Mt 9:17), the other is καινός (kainos), denoting the ‘new’ primarily in reference to quality (=fresh, unworn, that which as recently made is superior to what it succeeds, See Thayer-Grimm’s Lexicon). St John uses the latter adjective. Therefore the commandment is not merely of recent institution, but is intrinsically superior to the old commandment of love. The words that follow explain this superiority, “That you love one another as I have loved you.” The term καθως (kathos=’as’, ‘just as’) may mean, (1) in the same measure in which I have loved you (‘according as,’ i.e., in the degree that); (2) according to the type of love that I have given (in accordance with, just as); (3) on account of My love, because I have loved you (‘seeing that,’ i.e., agreeably to the fact that). Now, the first is impossible, for we are incapable for we are incapable of loving in the same degree and measure in which Christ loved. The second and third are not mutually exclusive; but the second, without excluding the third (1 Jn 4:10), is more prominent in the teaching of St John (see 15:12-13; 1 Jn 3:16), and it goes beyond the ‘Thou shalt love thy neighbor as thyself,’ of the O.T. Besides, the motive power is greater, ‘because Christ loved us,’ i.e., Christ’s own living example is a powerful incentive not found in the O.T., to imitate the type of His disinterested love. This love is not only commanded, but is also the distinctive mark and test of Christ’s perfect disciples (vs 35).”
These words come immediately before his warning about the hatred of the world (15:18ff.).
Joh 13:35 By this shall all men know that you are my disciples, if you have love one for another.
This love of the disciples is the greatest witness to Jesus, and its lack the greatest obstacle to it.
The Catholic Commentary On Holy Scripture: “Jesus’ intention in loving us was that we should love similarly—unselfishly (Cyr.), gratuitously (Chrys.), efficaciously, rightly (Aquin.). 35. Charity is the badge of true disciples of Christ. Tertullian ( Apol.30) sets it down as a note which pagans recognized in the Christian community. 1 Jn is full of the exegesis of this commandment. We should also recall the precious information transmitted by St Jerome (in Gal.) that St John in extreme old age could preach nothing else but ‘My little children, love one another’. Aug. has the beautiful thought: As Christ the Saviour loved us to save us, so charity should be a thirst for the spiritual salvation of our neighbours, all of whom God wills to be saved. It is primarily amongst disciples in the Christian community, but extends to others without exception, that they also may be disciples.”
Cornelius a Lapide: “In this shall all men know that ye are My disciples, if ye have love towards one another. My school is the discipline of love. If, then, you desire to follow Me as your Teacher, to be My disciples, and to be recognised as such by all men, love one another. This privilege is granted, therefore, only to charity. For it is not miracles that constitute us disciples of Christ, nor intellect, nor eloquence, nor strength, nor anything else but only love, says S. Chrysostom. For He is the Master, Leader, Prince, and Chief of love. Hence Paul says, Rom_13:8, “He that loveth his neighbour hath fulfilled the law.” Such were the early Christians of whom Luke, Act_4:32, says, “And the multitude of them that believed had one heart and one soul, and had all things in common.””
Constitution Of The Holy Apostles, Book II: “Let him also be merciful, of a generous and loving temper; for our Lord says: “By this shall all men know that ye are my disciples, if ye love one another.””
The Second Epistle Of Zephyrinus: “Assist ye, therefore, one another in good faith, and by deed and with a hearty will; nor let any one remove his hand from the help of a brother, since “by this,” saith the Lord, “shall all men know that ye are my disciples, if ye have love one to another.””
The Second Epistle Of Pope Fabian: “Ponder these things, and minister comfort to the brethren in all things; for, as the Truth says in His own person, “By this shall all men know that ye are my disciples, if ye have love one to another.”
Vatican II’s Decree On The Apostolate Of The Laity (#8): “While every exercise of the apostolate should be motivated by charity, some works by their very nature can become specially vivid expressions of this charity. Christ the Lord wanted these works to be signs of His messianic mission (cf. Matt. 11:4-5).
“The greatest commandment in the law is to love God with one’s whole heart and one’s neighbor as oneself (cf. Matt. 22:37-40). Christ made this commandment of love of neighbor His own and enriched it with a new meaning. For He wanted to equate Himself with His brethren as the object of this love when He said, “As long as you did it for one of these, the least of My brethren, you did it for Me” (Matt. 25:40). Assuming human nature, He bound the whole human race to Himself as a family through a certain supernatural solidarity and established charity as the mark of His disciples, saying, “By this will all men know that you are My disciples, if you have love for one another” (John 13:35).