Thomas Aquinas Commentary John 17:20-23

"Neither for these only do I pray, but for them also that believe on me through their word; that they may all be one; even as thou, Father, [art] in me, and I in thee, that they also may be in us: that the world may believe that thou didst send me. And the glory which thou hast given me I have given unto them; that they may be one, even as we [are] one; I in them, and thou in me, that they may be perfected into one; that the world may know that thou didst send me, and lovedst them, even as thou lovedst me." — John 17:20-23 (ASV)

1. After our Lord prayed for his disciples, he now prays in general for all the faithful (in chapter 17, lecture 3).

   First, we see his prayer. Second, he states why he should be heard: just Father, the world has not known you (John 17:25).

   In his prayer, he asks the Father two things for those who follow him: first, a perfect unity, and second, the vision of glory: Father, I will that where I am, they whom you have given me may also be with me (John 17:24).

   Regarding unity, he does two things: first, as man, he asks for a perfect unity. Second, as God, he shows that he gives them the ability to acquire this unity: and the glory which you gave me, I have given to them.

   In asking for unity, he first mentions for whom he is asking, and second, what he is asking for: that they all may be one.

2. He is praying for the entire community of the faithful. He says: I have asked that you protect my disciples from evil and sanctify them in the truth, but not for them only do I pray, but for those also who through their word will believe in me. This refers to those whose faith will be strengthened through their word—the word of the apostles. It is right for him to ask this, because no one is saved except by the intercession of Christ. Therefore, so that not only the apostles would be saved, but others as well, he also had to pray for these others. He loved your fathers and chose their descendants after them (Deuteronomy 4:37); their prosperity will remain with their descendants .

3. An objection is made that he does not seem to be praying for all his faithful, because he is praying only for those who would be converted by the word of the apostles. But the old fathers and John the Baptist were not converted by their word.

   We should answer that these persons had already arrived at their destination. Although they were not yet enjoying the vision of God, since the price had not yet been paid, they departed from this world with their merits, so that they would enter as soon as the gate was opened. Thus, they did not need such a prayer.

4. Again, what about others who did not believe through the word of the apostles, but through Christ’s word, as Paul did? I did not receive it from man, nor was I taught it, but it came through a revelation of Jesus Christ (Galatians 1:12). Or what of the thief on the cross (Luke 23:43)? It does not seem that Christ prayed for them.

   The answer, according to Augustine, is that those who believed through the word which the apostles preached—which is the word of faith ()—are said to believe through the word of the apostles, even if they did not hear the apostles directly.Tractates on the Gospel of John 109.2. The word of faith is called the word of the apostles because they were especially commissioned to preach it. This same word was divinely revealed to Paul and the thief on the cross.

   Alternatively, one could say that those who were converted directly by and through Christ, like Paul and the thief on the cross, are included in the part of the prayer where our Lord prayed for his disciples. And so our Lord said, whom you have given me (John 17:6), or will give me.

5. What about us, who do not believe through the apostles?

   We should say that although we do not believe directly through the apostles, we do believe through their disciples.

6. He prays for a perfect unity when he says, that they all may be one.

   First, he mentions the unity he is asking for. Second, he gives an example of it and its cause: as you, Father, in me. Third, he gives the fruit of this unity: that the world may believe that you have sent me.

7. He says: I am praying that they all may be one. As the Platonists say, a thing acquires its unity from that from which it acquires its goodness. For that which preserves a thing is good for it, and a thing is preserved only if it remains one. Thus, when our Lord prays that his disciples be perfect in goodness, he prays that they be one. Indeed, this was accomplished: now the company of those who believed were of one heart and soul (Acts 4:32); behold, how good and pleasant it is when brothers dwell in unity! (Psalms 133:1).

8. He gives an example of this unity and its cause, saying, as you, Father, in me, and I in you. Others are one, but in evil. Our Lord is not asking for this kind of unity, but for that which unites in good, that is, in God. And so he says, as you, Father, in me, and I in you, meaning, let them be united by believing in me and in you. We, though many, are one body in Christ (Romans 12:5); eager to keep the unity of the Spirit... one Lord, one faith, one baptism (Ephesians 4:3, 5). We are one or united in the Father and the Son, who are one; for if we were seeking different things to believe and desire, our affections would be scattered.

9. Arius uses this passage to argue that the Son is in the Father and the Father in the Son in the same way that we are in God. However, we are not in God by a unity of essence, but by a conformity of will and love. Therefore, he says, like us, the Father is not in the Son by a unity of essence.

   To this we should say that there is a twofold unity of the Father and the Son: a unity of essence and of love. In both of these ways the Father is in the Son and the Son is in the Father. The phrase as you, Father, in me, and I in you can be understood, according to Augustine, as referring to the unity of love. The meaning then is: as you, Father, are in me through love—because charity makes one be with God.Tractates on the Gospel of John 110.1. It is like saying: as the Father loves the Son and the Son loves the Father, so the disciples love the Father and the Son. In this case, the word as does not imply equality but a remote likeness.

   Alternatively, according to Hilary, this statement can refer to a unity of nature.The Trinity 8.10–11. This is not to say that the same numerical nature is in us and in the Father and the Son, but that our unity resembles that of the divine nature, by which the Father and the Son are one. In this case, the word as indicates a certain imitation. That is why we are invited to imitate divine love: be imitators of God, as beloved children, and walk in love, as Christ loved us (Ephesians 5:1–2). And we are also to imitate the divine perfection or goodness: you, therefore, must be perfect, as your heavenly Father is perfect (Matthew 5:48).

10. He indicates the fruit of this unity when he says, that the world may believe. For nothing shows the truth of the Gospel better than the charity of those who believe: by this all people will know that you are my disciples, if you have love for one another (John 13:35). This will be the fruit of unity: because if my disciples are one, the world may believe that the teaching I gave to them is from you, and know that you have sent me. For God is a cause of peace, not of contention.

11. A problem arises here. If we will be perfectly one in our heavenly homeland, where we will not believe but see, it seems out of place to say, after mentioning unity, that the world may believe that you have sent me.

    Our reply is that our Lord is speaking here of the unity that is taking shape on earth, not of perfected unity in heaven.

12. There is another problem. Our Lord is praying that those who believe in him may be one; therefore, the believing world is itself one. How then can he say, after the world has become one, that the world may believe?

    One can answer by giving the mystical sense. In this sense, our Lord is praying that all believers be one. Yet not all would believe at the same time; some would be the first to believe, and they would convert others. So when he says, that the world may believe, it refers to those who did not believe at first but became one when they did believe. The same applies to those who would believe after them, continuing to the end of the world.

    Hilary has another interpretation: the words that the world may believe indicate the purpose of their unity and perfection.The Trinity 8.12. It is like saying: you will perfect them so that they may be one, for this purpose, that the world may believe that you sent me. Here the word that indicates a final cause.

    A third interpretation is by Augustine.Tractates on the Gospel of John 110.2. For him, that the world may believe is another petition. In this case, the phrase I pray has to be repeated, so that the sense is: I pray that they may be one, and I pray that the world may believe.

13. Christ’s part in establishing this unity is mentioned when he says, the glory which you gave me, I have given to them, since what he is asking for as man he is accomplishing as God.

    First, he shows that he acted to make them one. Second, he mentions the kind and degree of this unity: I in them and you in me. And third, we see the purpose of this unity: that the world may know that you sent me.

14. He says: although, as man, I am asking for their perfection, still I am accomplishing this together with you. For the glory of my resurrection, which you, Father, gave me by an eternal predestination, and which you will soon give me in reality, I have given to them, my disciples. This glory is the immortality which the faithful will receive at the resurrection, an immortality even of the body: who will change our lowly body to be like his glorious body (Philippians 3:21); it is sown in dishonor, it is raised in glory (1 Corinthians 15:43). And this is so that they may be one, because by the fact that they have glory they will be made one, as we also are one.

15. He seems to be distinguishing his own activity from that of the Father, for he says that the Father gave him glory, and Christ gave this to his faithful.

    If this is understood correctly, we see that he is not saying these things to distinguish their activities, but their persons. For the Son, as Son, gives glory to Christ in his human nature together with the Father; and Christ, together with the Father, gives it to the faithful. But because Christ gave glory to his faithful especially through his own human nature, he attributes this giving to himself, while he attributes to the Father the giving of glory to his own human nature. This is the opinion of Augustine.Tractates on the Gospel of John 110.3.

    Or, according to Chrysostom, the glory—that is, the glory of grace—which you gave me in my human nature, giving me a superior knowledge, perfection, and power to perform miracles, I have given to them in a limited way, and will give it later more fully.Commentary on Saint John 82.2. We are being changed into his likeness from one degree of glory to another (2 Corinthians 3:18); you have given gifts to men (Psalms 68:18). And this is in order that they may be one, as we also are one, for the purpose of God’s gifts is to unite us in a unity that is like the unity of the Father and the Son.

16. The manner of this unity is added when he says, I in them and you in me. They arrive at unity because they see that I am in them, as in a temple—do you not know that you are God’s temple and that God’s Spirit dwells in you? (1 Corinthians 3:16)—by grace, which is a certain likeness of the Father’s essence, by which you, Father, are in me through a unity of nature: I am in the Father and the Father is in me (John 14:10). And this is in order that they may be made perfect in one.

    Above, he had said, that they may be one, while here he says, perfect in one. The reason for this is that the first time he was referring to the unity brought about by grace, but here to its consummation. Hilary gives another interpretation: I in them, that is, I am in them by the unity of human nature, which I have in common with them, and also because I give them my body as food; and you in me, by a unity of essence.The Trinity 8.13.

17. Referring to the first explanation, since the Father, as well as the Son, is in them by grace—we will come to him and make our home with him (John 14:23)—why then does he say, I in them, without mentioning the Father?

    According to Augustine, he does this not to mean that the Son is in them without the Father, but because they have access to the Father through the Son: we have peace with God through our Lord Jesus Christ. Through him we have obtained access (Romans 5:1–2).Tractates on the Gospel of John 110.4.

    Or, according to Chrysostom, Christ previously said, we will come to him (John 14:23), to indicate that there is a plurality of divine persons, contrary to Sabellius.Commentary on Saint John 82.2. But here he says, I in them, to indicate the equality of the Father and the Son, contrary to Arius. We can understand from this that it is enough for the faithful if the Son alone dwells in them.

18. The purpose of this unity is given when he says, that the world may know that you sent me. If perfect in one refers to the perfection of this life, then that the world may know is the same as what he said before, that the world may believe. The word "believe" would indicate just a beginning state. But here he says, know, because complete knowledge, not faith, comes after imperfect knowledge.

    He says, that the world may know, not the world as it is now, but as it was, so that the meaning is: that the world, now a believing world, may know. Or, that the world, that is, the lovers of the world, may know that you have sent me. For by that time, those who are evil will know by clear signs that Christ is the Son of God: every eye will see him (Revelation 1:7); they will look on him whom they have pierced (John 19:37); they will see the Son of Man coming in a cloud with power and great glory (Luke 21:27).

19. The world will not only know this, but it will also know the glory of the saints, and that you loved them. At the present time, we cannot know how great God’s love for us is. This is because the good things that God will give us exceed our longings and desires, and so cannot be found in our heart: no eye has seen, nor ear heard, nor the heart of man imagined, what God has prepared for those who love him (1 Corinthians 2:9).

    Thus the believing world, that is, the saints, will then know by experience how much God loves us. But the lovers of the world, that is, the wicked, will know this by seeing in amazement the glory of the saints: This is the man whom we once held in derision and made a byword of reproach ; and it continues, Why has he been numbered among the sons of God? And why is his lot among the saints? .

20. He continues, as you also loved me. This does not imply an equality of love, but a similarity and a reason. It is like saying: the love you have for me is the reason and cause why you love them, for by the fact that you love me, you love those who love me and are my members: the Father himself loves you, because you have loved me (John 16:27).

    God loves all the things he has made by giving them existence: for you love all things that exist, and have loathing for none of the things you have made . But above all he loves his only Son, to whom he has given his entire nature by an eternal generation. In a lesser way, he loves the members of his only Son—that is, the faithful of Christ—by giving them the grace by which Christ dwells in them: he loved his people; all those consecrated to him were in his hand (Deuteronomy 33:3).