As he ends a long prayer to his Father, Jesus prays for his disciples and future believers. He asks that his followers might be unified, bearing witness to God's love.
At the conclusion of the Last Supper, Jesus prays that all his followers might be one. His prayer looks forward to the time after Easter, when his disciples will bring many to faith through the witness of the gospel. According to John's Gospel, unity is an expression of love. Christians find their unity in the love they receive from God, and they express this unity in the love they give to others. John's Gospel does not assume that Christian unity requires any one form of church organization. All of Jesus' followers are simply known as "disciples" in John's Gospel. Unity happens wherever Christians are commonly rooted in the love of Christ, and it is expressed whenever Christians join together in love and witness.
20 I ask not only on behalf of these, but also on behalf of those who will believe in me through their word, 21that they may all be one. As you, Father, are in me and I am in you, may they also be in us,* so that the world may believe that you have sent me.
New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org