While studying for my message this past week, “Praying One: learning to pray for unity from Jesus’ Prayer,” I encountered this insightful explanation from Andrew T. Lincoln about how Jesus’ prayer for unity relates to the mission of the church.

Jesus’ first petition for all believers, ‘that they may all be one’ (v. 21), is a request for unity—both for the disciples and for those who will come to believe through their witness. It is clear that what is envisioned is a unity that results from believers participating in the foundational unity that already exists between the Father and the Son. Again, the grounds for the petition follow. In verses 22-23 Jesus states that he has already laid the basis for the unity requested in the petition by giving to the disciples the glory that the Father has given him. God’s glory—that is, the honor and reputation of the divine name—has been bestowed on Jesus. Jesus, therefore, has granted to his followers a share in that glory by making known to them the divine name (v. 6) and by enabling them to share in his own reputation and honor (v. 10b).

This complete unity between Father, Son, and believers (‘As you, Father, are in me and I am in you, may they also be in us,’ v. 21a) has as its goal the world’s coming to know the truth about Jesus’ mission: ‘so that they world may believe that you have sent me” (v. 21b). Its purpose, however, is not only knowledge about Jesus. It is also that the world might know the truth about believers’ relationship to God—a relationship in which they, as well as Jesus, are loved by God: ‘so that the world may know that you have sent me and have loved them even as you have loved me’ (v. 23; cf. 14:21-23).

The community in which the believers’ witness is embodied is to be a united one, and the issues at stake in Jesus’ mission hinge on the reality ‘that they may become completely one, so that the world may know that you have sent me’ (v. 23b). Since the truth established in the cosmic trial has to do with the unity that exists between the One who is sent and the One who has sent him, it is not surprising that the testimony to that truth is to be displayed by the oneness of the witnesses.

It is not simply that the unity of the witnesses mirrors the unity that exists between the Father and the Son. Rather, the unity of the believing community actually participates in the unity that defines the relation between Jesus and God (cf. v. 21). For the goal of its mission is not only that the world comes to know Jesus’ identity as the One sent by God, but also that it comes to know that his followers are loved by God just as Jesus is loved by God (v. 23c). How does the world come to know God as love? Not only through hearing the witness that Jesus’ death was God’s loving gift to the world, but also through seeing and experiencing the enacted witness of a community that is united in loving acceptance of one another.

Andrew T. Lincoln, “God’s Name, Jesus’ Name, and Prayer in the Fourth Gospel,” in Into God’s Presence: Prayer in the New Testament, ed. Richard N. Longenecker (Grand Rapids, MI: Eerdmans, 2002), 168-169.