17:20 Jesus now identified future believers as the objects of His intercession, as well as the Eleven. He described them as those who would believe through the witness of the Eleven. All Christians have come to Jesus Christ either directly or indirectly through one or another of the original eleven disciples or apostles. As we have seen, John had a special interest in stressing the importance and effectiveness of the witness of believers. This witness is the concrete expression of the mission to which Jesus had been referring (vv. 18-19). Even though the Eleven would fail Jesus soon, they would return to follow Him and would carry on the mission that He gave them.
17:21 Jesus prayed for the unity of all believers as well as for the unity of the Eleven (v. 11). This unity rests on adherence to God's truth, and it reflects the unity that exists between the Father and the Son. Furthermore it is union with the Father and the Son (cf. ch. 15). God answered this prayer initially on the day of Pentecost when He united believers with Himself in the body of Christ, the church (cf. 1 Cor. 12:13).
The purpose of this unity is that the world might believe that the Father sent the Son, namely that Jesus was God's Son. The display of mutual love among Jesus' disciples shows that they are His disciples. Their love for one another shows that they really do follow His teachings and possess His life. This gives evidence that Jesus really was who He claimed to be. It vindicates His teaching and so glorifies Him.
"From the beginning of the believer's spiritual life to his final glorification the fatherhood of God is the basis for the believer's experience. . . . This relationship of God to men, perfectly exemplified in the life of the Lord Jesus Christ, is both the highest expression of His consciousness of His relation to God and the fullest attainment that man can reach through union with Him."528
This verse is a favorite of promoters of the ecumenical movement. However as the content and context of this verse clarify, Jesus was not speaking about institutional unity but personal unity among genuine believers. He was praying that all true believers would be one in their love for one another, their submission to the authority of Scripture, and their commitment to their mission. Disunity among professing Christians has frustrated Jesus' purpose that the world might believe on Him. Nevertheless the solution to this problem is not to impose an artificial institutional unity that ignores the bases of true unity and presents a hypocritical facade of oneness. It is to promote love for one another among genuine believers.
17:22 Jesus continued to explain the nature of the unity that He requested from His Father. In what sense do all believers share God's glory? Jesus probably was speaking of His bringing the full knowledge of God to them. The revelation of God results in glory for God. When believers understand and believe the revelation of God that Jesus brought, they become partakers of that glory. This is something else they share in unity with one another that the Father and the Son also share with one another. Another view is that the glory in view refers to Jesus' work of redemption, but that subject is not as prominent in the context as the revelation of God.
17:23 This verse advances the thought of verse 21. Jesus wanted the unity among believers to be so great and so clear that the world would believe Jesus' message. The world would also see that God had poured out His love on believers as well as Jesus. Notice that Jesus implied that He would indwell believers as the Father indwelt Him. All three members of the Godhead indwell the Christian (14:23; Rom. 8:9; Col. 1:27). God's indwelling presence unites Christians in the body of Christ and glorifies God.
