What to Think about Oneness
But how should we think about the oneness or wholeness that this prayer describes?
New Testament scholar Richard Bauckham is helpful on this question. He describes the “oneness” theme in the gospel of John as including two different dimensions of the meaning of “one.” First, oneness can refer to uniqueness, and this seems to be the case in the first part of the teaching of the Shema (Deut. 6:4–9). God is one. He is unique. He is God alone, unlike any other. This teaching about the uniqueness of God seems to be the way in which the Shema was received in the historical context of the New Testament as well.
So how is the Lord one, if He is three persons? Bauckham writes of the John 17 passage in question:
Commentators tend not to notice the allusion to the Shema here, but the word “one” could not fail to recall the Shema for any Jewish hearer or reader. The Father and the Son are one in their communion with each other. Jesus is claiming that the unique deity of the God of Israel consists in the communion between Father and Son. To assert this kind of oneness, the oneness of personal community of God, is unprecedented in early Judaism.
But oneness can have another meaning. Oneness can refer to the unified character of a thing or person. This seems to be the meaning that is used in the second part of the Shema to describe the unified wholeness of the people of God: their hearts, souls, and strength are unified by the love of the Lord. Bauckham rightly points out that the Old Testament includes multiple instances of this sort of unified oneness of the people (Isa. 45:20; Ezek. 34:23; 37:15–24; Mic. 2:12; Hos. 1:11). Such a notion of oneness was present in the sectarian communities of the Judean desert in and around Qumran who referred to their group as the yehad, a term closely connected to the idea of oneness found in the Old Testament (Mic. 2:12). Yehad is often translated as “community,” an English word whose etymology also reflects this notion of oneness or unity.
In His High Priestly Prayer, Jesus acknowledges the restoration promise of a community unified by the love of the Lord, but He sees His union with His people as the basis of the loving unification experienced by them as a group. Because of His place in the Trinity and His union with His people, Jesus provides the means by which His followers can participate in the loving wholeness of the God in three persons.
The Better Unity
Here we find an instance of how the new covenant of Christ is a greater, better arrangement than the Mosaic covenant. To understand how this is the case, we must, in effect, “read backwards” by engaging the Shema of Moses through the lens of the High Priestly Prayer. The call to wholeness and love in Deuteronomy 6 is not a failure on its own terms, but it is improved and made clearer in the new covenant. By understanding how Jesus accomplishes our union with Him and makes us partakers of the loving oneness of the Godhead, we can see what the Shema lacked in its language. Yes, our love must flow as a natural response to the character of the Lord as our God and as one, but in order to fully grasp how such love is possible, we must turn to our union with Christ.
It is only through union with Christ that the people of God can rightly love the Lord in the way that His character requires. Just as one cannot say Jesus is Lord and mean it without the Spirit of Christ saying it through us (1 Cor. 12:3), so one cannot truly love the Lord and others without the Spirit of Christ loving God and others through us.
Finally, we should address Christ’s stated goal: “The glory that you have given me I have given to them, that they may be one even as we are one, I in them and you in me, that they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me” (John 17:22–23).
As we think about the goal of love, its telos, we find that like its origin, the goal of love is Trinitarian. Jesus asks that His people be unified in Him so that their love will be known throughout the world. As in the Shema, the love of the people is not meant to be a private endeavor but rather a public proclamation. The goal of our union with Christ is that the world might know the love of the Father for the Son in the Spirit.