John 17:20 - Meaning and Application

Next to purity, Christ prays for unity. Wisdom from above is first pure, then peaceable, and friendship is truly lovely when it is like the oil on Aaron’s holy head, or the dew on Zion’s holy hill.

Notice first who is included in this prayer (John 17:20): “Not these only,” meaning not only the disciples then with him, the eleven apostles, the seventy, and others, men and women who followed him on earth, “but also those who will believe in me through their word,” whether preached in their own day or written for later generations. He prays for them all, that they may share in this prayer and receive its benefit.

Only those who believe, or will believe, in Christ are included in Christ’s mediation, his work of coming between God and sinners. That name, believer, includes the whole life and duty of a Christian. Some believed when they saw him, but later generations have not seen him and yet have believed. It is through the Word that people are brought to faith in Christ, and that is why Christ appointed the Scriptures to be written and a lasting ministry to remain in the church as long as the world stands, so that a people may be gathered for God.

Christ also knows exactly who will believe in him. He is not praying at random, as if everything depended on the uncertain will of man, which claims freedom but is actually held in bondage by sin. No, Christ knew well whom he prayed for. The matter was settled by God’s foreknowledge and purpose. He knew who had been given to him, who were appointed to eternal life, whose names were in the Lamb’s book, and who would certainly believe (Acts 13:48).

Jesus intercedes not only for the great and well-known believers, but also for the smallest and weakest. He does not pray only for those who will serve in the highest places of honor in his kingdom, but for all, even those the world considers unimportant. As God’s care reaches down to the least creature, so his grace reaches down to the least Christian. The good Shepherd keeps his eye even on the poor sheep.

Christ also had real concern, in his prayer, for those of the chosen remnant who were not yet born, the people who would be created (Psalm 22:31), the other sheep he still had to bring. Before they are formed in the womb, he knows them (Jeremiah 1:5). Prayers for them were, so to speak, already laid up in heaven by the one who declares the end from the beginning and calls things that are not as though they were.

Next, what does Christ mean by this prayer, “that they all may be one” (John 17:21)? He says the same thing earlier (John 17:11), and again later (John 17:22). His heart was deeply set on this. Some think the oneness in John 17:11 especially refers to the disciples as ministers and apostles, so that they might be one in their witness to Christ. In that sense, the harmony of the Gospel writers and the agreement of the first preachers of the gospel came from this prayer. They were to be not only of one heart, but also of one mouth, speaking the same truth. The unity of gospel ministers is both the beauty and the strength of the gospel cause.

But it is clear that the oneness in John 17:21 includes all believers. This is Christ’s prayer for all who belong to him, and we can be sure it is an answered prayer, that they all may be one, one in us (John 17:21), one as we are one (John 17:22), made perfect in one (John 17:23). It includes three things. First, they are to be joined into one body. The Father is asked to regard them all as one, and to confirm that great charter by which they are formed into one church. Though they live in many places, from one end of heaven to the other, and in many ages, from the beginning to the end of time, so that they cannot know one another personally, still they are to be united in Christ, their common head. As Christ died, so he prayed, to gather them all into one (John 11:52; Ephesians 1:10).

Second, they are to be animated by one Spirit. That is clearly included in the words, “that they may be one in us.” Union with the Father and the Son is received and kept only by the Holy Spirit. “He who is joined to the Lord is one spirit” (1 Corinthians 6:17). Let them all bear the same image and mark, and be moved by the same power.

Third, they are to be bound together in love and kindness, all of one heart. “That they all may be one” means, first, one in judgment and outlook. Not in every small detail, for that is neither possible nor necessary, but in the great truths of God they are agreed by virtue of this prayer. They agree that God’s favor is better than life, that sin is the worst evil, that Christ is the best friend, and that there is another life after this. It also means one in spirit and desire. All who are sanctified share the same divine nature and image. They have a new heart, and in that sense it is one heart. They are one in their goals and aims. Every true Christian, so far as he is truly Christian, looks to God’s glory as his highest end and heaven’s glory as his greatest good.

They are also one in their desires and prayers. Though they differ in words and style, they have received the same spirit of adoption and follow the same rule, so they pray for the same things in substance. Finally, they are one in love and affection. Every true Christian has something within him that draws him to love all true Christians as such. Christ is praying for that fellowship of saints we confess in the creed, the sharing all believers have with God and their close union with all the saints in heaven and on earth (1 John 1:3). Yet this prayer will not be fully answered until all the saints come to heaven, for then, and only then, they will be made perfect in one (John 17:23; Ephesians 4:13).

There is also a reason given for this request, and it rests on the relationship between the Father and the Son, which is repeated again and again (John 17:11, John 17:21-23). First, it is assumed that the Father and the Son are one, one in nature and essence, equal in power and glory, and one in mutual love. The Father loves the Son, and the Son always pleases the Father. They are one in purpose and one in action. Their deep unity is shown in the words, “You in me, and I in you.” Christ often mentions this for support while facing suffering, when his enemies were ready to seize him and his friends were about to scatter. Yet he was in the Father, and the Father in him.

Second, this oneness is used in Christ’s prayer for his disciples’ oneness. It serves as the pattern of the unity he wants for them. Believers are one in some measure as God and Christ are one. First, their union is close and real. They are joined by a divine nature, by the power of divine grace, and in line with God’s own purpose.

Secondly, this is a holy union, formed by the Holy Spirit for holy purposes. It is not a political body for any worldly use. Thirdly, it is, and will finally be, a complete union. The Father and the Son have the same qualities, traits, and perfection, and believers now share that likeness as far as they are made holy. When grace is finished in glory, they will match each other perfectly, all changed into the same image.

This is also the center of that oneness, that they may be one in us, all coming together here. There is one God and one Mediator, that is, one who brings us to God. Believers are one in this: they all agree to depend on the favor of this one God for their happiness, and on the merit of this one Mediator for their right standing with God. A union that does not center on God as the goal and Christ as the way is not a true union, but a conspiracy. All who are truly joined to God and Christ, who are one, will soon be joined to one another.

It is also a plea for that oneness. The Creator and Redeemer are one in purpose and interest, but what good is that if all believers are not one body with Christ? What good is it if they do not together receive grace after grace from him, as he has received it for them? Christ’s purpose was to bring fallen humanity back to God. “Father,” he says, “let all who believe be one, so that in one body they may be reconciled” (Ephesians 2:15-16). This especially points to the joining of Jews and Gentiles in the church, that great mystery, that Gentiles should be fellow heirs and part of the same body (Ephesians 3:6). I think this is the main focus of Christ’s prayer, because it was one of the great things he aimed for in his death.

The words, I in them, and you in me, show what this union is, and how necessary it is, not only for the beauty of his church, but for its very existence. First, there is union with Christ, “I in them.” Christ living in the hearts of believers is the life and soul of the new person. Second, there is union with God through him, “You in me,” so that through Christ God is in them. Third, there is union with one another that comes from these, “that they may be made perfect in one.” We are complete in him.

Christ also means this in all the light and grace he gives them (John 17:22): “The glory which you gave me, as the trustee or channel of it, I have given them, for this purpose, that they may be one, as we are one.” So these gifts are wasted if they do not make believers one. Some of these gifts were given to the apostles and the first founders of the church. The glory of being God’s messengers to the world, the glory of working miracles, and the glory of gathering a church out of the world and setting up God’s kingdom among people, this glory was given to Christ, and he shared some of it when he sent them to make disciples of all nations.

Or these are the gifts given in common to all believers. The glory of being in covenant with the Father, accepted by him, held close in his love, and planned for a place at his right hand, was the glory the Father gave to the Redeemer, and he has confirmed it to those redeemed by him. He says he has given this honor to them because he intended it for them, settled it on them, and secured it for them, if they believe. Christ’s promises are real gifts. It was given to him to give to them. It was entrusted to him for their benefit, and he was faithful to the one who appointed him. He gave it to them so they might be one.

First, this gives them the privilege of unity. Because they share one Father and one Lord Jesus Christ, they may truly be called one. The gift of the Spirit, that great glory the Father gave to the Son to be given to all believers, makes them one, because he works all things in all believers (1 Corinthians 12:4). Second, it calls them to the duty of unity. Since they share one faith and one covenant, one Spirit and one Bible, since they share one God and one Christ, and hope for one heaven, they should be of one mind and one voice. Worldly glory stirs up rivalry, because if some are lifted up, others are pushed down. That is why the disciples, while they dreamed of a worldly kingdom, kept arguing. But spiritual honors are given equally to all Christ’s people. They are all made kings and priests to our God, so there is no reason for competition or envy. The more Christians are occupied with the glory Christ has given them, the less they will want empty praise, and the less they will quarrel.

He also points to the good influence their oneness would have on others and the public good it would promote. This is pressed twice here, “That the world may believe that you have sent me” (John 17:21), and again, “That the world may know it” (John 17:23), for without knowledge there can be no true faith. Believers must know what they believe, and why they believe it. Those who believe blindly, take too much at risk.

Christ shows here his goodwill toward the world in general. In this he is fully in agreement with his Father, as we know he is in everything, that God wants all people to be saved and to come to the knowledge of the truth (1 Timothy 2:4; 2 Peter 3:9). Therefore, all possible means should be used, and no effort spared, to convince and turn the world. We do not know who are chosen, but in our own place we must do all we can to help people’s salvation, and be careful not to do anything that would hinder it.

He also shows the good fruit of the church’s unity. It will prove the truth of Christianity and help bring many to accept it. In general, it will give Christianity a better reputation in the world and among outsiders. First, the gathering of Christians into one society under the gospel covenant will strongly support Christianity. When the world sees so many who once belonged to it called out of its family, set apart from others, and changed from what they themselves once were, when they see this society raised by the seeming foolishness of preaching and upheld by miracles of providence and grace, and when they see how well it is shaped and ordered, they will be ready to say, We will go with you, for we see that God is with you. Second, the loving unity of Christians is the beauty of their faith, and it invites others to join them. The love among the first Christians (Acts 2:42-43; Acts 4:32-33) is an example of this. When Christianity, instead of causing quarrels about itself, makes other disputes die down, when it cools hot tempers, smooths rough spirits, and leads people to be kind, loving, polite, and generous to all, and to work for peace in every relationship and community, this will recommend it to all who have any sense of religion or natural affection.

In particular, this unity will lead people to think rightly about Christ and Christians.

First, it will make them see and believe that the Father sent Christ. They will know and believe that you sent me. This unity shows that Christ came from God and that his teaching is truly from God. It is hard to explain such deep harmony among people with different abilities, tempers, and interests in any other way. Christ must have been sent by the God of power, who shapes human hearts alike, and by the God of love and peace. When God’s people are one, then he is honored as one, and his name is one.

Second, it will make them think rightly about Christians. They will know that you have loved them as you have loved me. Here is the privilege of believers: the Father himself loves them with a love like his love for his Son. They are loved in Christ with an everlasting love. The evidence that we share in this privilege is our being one. It shows that God loves us when we love one another with a pure heart, because wherever God’s love is poured into the heart, it changes the heart into the same likeness.

Think how much good it would do in the world if people better understood how dear all true Christians are to God. The Jews had a saying, if the world only knew the worth of good people, they would surround them with pearls. Those who have so much of God’s love should also have more of ours.