1. In order to follow John’s testimony regarding the person and work of Jesus Christ, we must attend to the ways he describes Jesus’ oneness with the Father along with the ways John describes the natural kinship relation that grounds their oneness. These two ways of speaking about Jesus correspond to the two ways John identifies the Word in the Gospel’s opening verse, that is, by means of the Word’s relation to God (“the Word was toward God”) and by means of what the Word holds in common with God (“the Word was God”). In addition to these two ways of describing the person and work of the Son of God, John provides a third: the way of “mutual indwelling.” Unlike the preceding two patterns of speech, which may be found across the broader NT corpus, this pattern appears to be original to John.
2. In response to the charge of blasphemy in John 10:38, Jesus argues that, if his opponents will not accept his words, they should at least accept what his works manifest, namely, “that the Father is in me and I am in the Father.” In John 14:10-11, Jesus repeats an identical line of argument in response to Philip’s request that Jesus “show” the disciples the Father. Jesus not only applies the language of mutual indwelling to the Father-Son relation. He also applies this language to the relationship between the Trinity and his disciples. In John 6, Jesus says, “Whoever eats my flesh and drinks my blood abides in me, and I in him” (Jn 6:56). In the Farewell Discourse, Jesus (1) promises the disciples that the three persons of the Trinity will indwell them (Jn 14:17, 20, 23), (2) calls the disciples to a life of mutual indwelling with himself via the vine metaphor (Jn 15:1-10), and (3) prays that the community “gathered into one” (Jn 11:52; cf. 10:16) as the result of his completed work will enjoy the mutual indwelling of the Father’s love of the Son and the Son’s love of the Father (Jn 17:21-26). Note that, unlike the first two patterns of speech, which distinguish the persons of the Trinity from creatures, this pattern of speech (in some way) connects the Trinity and creatures. Moreover, unlike the second pattern of speech, which describes the asymmetrical relation of the Father and the Son (where one is the Father and the other is the Son, where one gives and the other receives, etc.), the third pattern of speech describes the reciprocal relation, not only between the Father and the Son, but also between the persons of the Trinity and the community of disciples: “just as you, Father, are in me, and I in you, that they also may be in us,” “I in them and you in me” (Jn 17:21, 23).
3. What is the significance of this third pattern of speech in John’s trinitarian theology? In my opinion, “social trinitarian” theologians err in attempting to explain the first pattern of speech (what the Father and the Son hold in common as God) by means of the third pattern of speech (the mutual indwelling of the Father and the Son). The uniqueness of the Trinity as the one God cannot be reduced to the community of persons within God. Better, following Emmanuel Durand, to see the third pattern of speech, not as explaining the first or second patterns of speech, but as adding a further, deeper degree of insight into the life of the blessed Trinity. If the first pattern of speech indicates what the Father and the Son hold in common as God, while the second pattern of speech indicates the basis of what they hold in common as God, that is, the natural kinship relation of the Father and the Son, the third pattern indicates the enduring fruit of the relation whereby the Father and the Son hold in common what they hold in common, that is, a life of mutual, indwelling love. This interpretation is confirmed by the way John applies the analogy of mutual indwelling to the vine-branches relation in John 15. The mutual indwelling of the vine and the branches is not what establishes their relation—“already you are clean because of the word I have spoken to you” (Jn 15:3). Rather, the mutual indwelling of the vine and the branches is what maintains their relation as a fruitful relation: “Abide in me, and I in you. As the branch cannot bear fruit by itself, unless is abides in the vine, neither can you, unless you abide in me” (Jn 15:4).
4. This interpretation clarifies how the analogy of mutual indwelling extends, across the creator-creature distinction, from the Trinity to the community of disciples. When Jesus prays that the community of disciples “may all be one, just as you, Father, are in me, and I in you, that they also may be in us” (Jn 17:21), he is not praying that the community of disciples will become the one God, a prayer that would violate the first principle of both Jewish and Christian religions (Deut 6:4; Mark 12:28-29). Instead, Jesus is praying that the eschatological community of disciples, brought into being as the result of his completed work, will enjoy a oneness that reflects the mutual, loving communion of the persons of the Trinity by means of mutual, loving communion with the persons of the Trinity. According to John’s Gospel, the community chosen by the Father and redeemed by the Son is destined for union and communion with the blessed Trinity by the indwelling of the Holy Spirit (Jn 14:15-17, 20, 23; 17:1-26; cf. Eph 4:1-6). This union and communion, in turn, is the basis and goal of the community’s mission to the world.
 Richard Bauckham, Gospel of Glory, 12.
 See Table 1.2 in Bauckham, Gospel of Glory, 11.
 The first pattern of speech describes what the Father and the Son hold in common, over against creatures, as the one God. The second pattern of speech distinguishes the Father’s relation to his monogenēs from his relation to the rest of his creaturely “children.”
 Emmanuel Durand, “Perichoresis: A Key Concept for Balancing Trinitarian Theology,” 182.
 For an example of this line of interpretation, see Bauckham, Gospel of Glory, 32-39. For a helpful recent response, see Wesley Hill, “In Defense of ‘Doctrinal Exegesis’: A Proposal, with Reference to Trinitarian Theology and the Fourth Gospel.”
 Emmanuel Durand, “Perichoresis.”
 Bauckham’s discussion of the OT distinction and correspondence between the uniqueness of God and the unity of the eschatological community is helpful background to John’s theology at this point. See Bauckham, Gospel of Glory, chap. 2.
 Köstenberger and Swain, Father, Son and Spirit: The Trinity and John’s Gospel, chap. 9.