“I do not ask for these only, but also for those who will believe in me through their word, that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. (Jn. 17:20-21)
Jn. 17:21, located in the midst of Jesus' High Priestly prayer, has Jesus praying for the unity of all believers, that they may be one. It has thus been used by the ecumenically minded to promote their ecumenism, supposedly to fulfil Jesus' prayer that believers will be one.
It cannot be denied that Jesus did indeed pray that believers are to be united, and we are exhorted to maintain the unity in the Spirit (Eph. 4:3) and have unity of mind (1 Peter 3:8), living in harmony with each other (Rom. 12:16). Unity therefore is a good thing that Christians are to have.
As we look into the context however, we can see a few points which undermine the ecumenical movement, and show us the biblical way in which such unity is to be achieved.
The first thing to note in the context is that such unity is to be achieved and grounded in the truth (Jn. 17:17). Therefore, taking a stand on God's truths is important and is in fact the basis of the unity Jesus prayed for.
Secondly, Jesus in His High Priestly prayer makes a sharp distinction between those who are His (the elect) and those who are of the world. Jesus explicitly states that He did not pray for the world (v. 9), and therefore the prayer of unity only encompasses believers (those who are His) and not unbelievers (the world). The call for unity therefore presupposes that those involved are truly believers, as the world is NOT to be united with. Elsewhere in Scripture, we are told to separate from the world and all ungodly partnerships (2 Cor. 6:14-18). This leads us to two sub-points with regards to the call to unity.
- The ecumenical movement err in attempting to find common ground with the world of unbelievers.
- Discerning whether the other party is a Christian is logically prior to seeking unity with that party. For if the other party is not really a Christian, then attempting such unity is not in line with Jesus' prayer in distinguishing believers from the world.
Lastly, true biblical unity is to be maintained, not created. Jesus in His prayer is heard by the Father and since He perfectly knows God and His will (Mt. 11:27), his prayer is in line with God's will and will be answered. And even if it is to be created, the prayer is offered to God not to us, so God the Father is the one who will answer and fulfil the prayer request. Nevertheless, Scripture tells us that this unity is indeed already present in Christ and we are to maintain it (Eph. 4:3), not to create it. The ecumenical movement therefore is in error for seeking to create a semblance of unity instead of preserving the already present unity in the Body of Christ, around the common confession of the Faith (Eph. 4:5-6).
John 17:20-21 therefore does not in any shape reformed support any form of ecumenism. Rather, we are to strive to maintain the unity around the truth with fellow believers, not attempting to create bridges where there are none and are forbidden.