21 that they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me.
Jesus now prayed for the specific needs of future believers.
21 that [purpose] they all may be one,
Jesus prayed for unity among future believers. The world has no unity; it divides into many factions, a plethora of beliefs.
as [just as] You, Father, are in Me, and I in You;
The word “as,” or more accurately just as, expresses the pattern behind the principle of oneness. We can compare the relationship between the Father and Son to the relationship that believers have with God.
The Father and Son function as one; they are a unity. There is a mutual indwelling between them. The Son did exactly what the Father wanted in His mission on earth. He pleased the Father in everything (Jn 5:30; 8:29). The interrelationship of the Father and Son is the model for Christian unity.
that [result] they also may be one in Us,
The followers of Christ are to pattern their unity after the Father and Son. Oneness rests on direct relationship with God. That oneness is found “in Us,” in both the Father and Son. Here is the argument:
(1) The Father is in Jesus: “You in me.”
(2) Jesus is in the Father: “I in you.”
(3) Both are in believers: “I in them” and “May they also be in us” and “That they may be brought to complete unity.”
(4) The purpose of these indwellings is that the world may believe in the mission of the incarnation: “So that the world may believe that you have sent Me” and “To let the world know that you sent me.”
The argument is not that the unity among believers and God is the same as between the Father and Son. The point is that there is an analogy between the Father-Son indwelling and the God-believer indwelling. As the Father and Son are one yet distinct, so there is distinction between the oneness of believers and God. Fellowship with the unity of the Father-Son relationship will result in “that the world may believe.”
that [result] the world may believe that You sent Me.
If the body of Christ is one in message and orientation, then many will come to Christ. Fellowship among believers will be tangibly clear to a world without Christ. They will see more than a unity of love but will come to grips with the revelation of Christ’s mediation for the world.
Uniformity is not unity.
The Father and Son are one in unity, but they are not a uniformity. They are distinct from each other and have different functions. They are one being, one essence, but different persons.
The church should be one with God, His Son, and His Word. It is a unity of personal relationship—the same kind of unity as between the Father and Son. Indwelling is the model for relationships. It is the foundation for the relationship between the Father and Son. It is also the basis for fellowship among believers.
The ecumenical movement uses verse 21 for their cause. This group attempts to unify denominations based on the evisceration of truth. Uniformity is not unity. People can deny the deity of Christ or accept it; it makes no difference to them. This is not the point of Jesus’ prayer. Genuine unity cannot gloss over doctrine.
Our Lord did not pray for institutional oneness but a unity of purpose, love, and truth. This is not organizational unity but organic unity, a unity of life that comes from God. It is a unity that carries the dynamic of faith. This involves diversity in unity (1 Co 12:4-6).
Every genuine believer belongs to the body of Christ (1 Co 12:13). This unity of identity should show itself in relationships among Christians. This is the same kind of unity found in the relationship between the Father and the Son.
Christians are not to live in isolation from the world. There is an onus on them to share the gospel with others.