Paul and Participation in Christ: An Introduction
Terminology, Meaning, Perspectives
Union with Christ is often said to be the central concept within Pauline theology.  Especially the theology of Calvin has put this concept at the center, which has the potential of harmonising the sometimes puzzling parts of Paul’s theology. But how do we even begin defining and understanding it without reverting to vague truisms? In this article I want to do five things:
- give an overview of important Pauline terms for this union and
- of important theological/systematic terms to describe it;
- summarise the meaning of the cross and resurrection of Christ and
- the way believers participate in it and in him; and
- put the transformation of believers in theological perspective.
1. Pauline Terminology
The words Paul uses to talk about this concept are κοινωνία (koinōnia, ‘fellowship’, ‘sharing’, ‘participation’), κοινωνέω (koinōneō, ‘to share, participate’) and κοινωνός (koinōnos, ‘partaker’, ‘sharer’).  Most basically, these terms denote a communal participation in the single gift of Christ and the Spirit (to use Barclay’s language).
Paul also uses prepositions to describe the union between believers and Christ:
- Every human is born outside of Christ (χωρὶς Χριστοῦ chōris Christou; Eph 2:12) and in another system of participation, namely Sin and Death (cf. Rom 6:1–8:7). This is the place ‘from’ (ἐκ ek) which we are rescued (Gal 1:3; Col 1:13). Through faith and baptism, believers move into (the realm of) Christ (εἰς Χριστὸν, eis Christon; faith: Gal 2:16, Phil 1:29; baptism: Rom 6:3–4, Gal 3:27; cf 1 Cor 12:13).
- Now believers can properly be described as ‘in Christ’ (ἐν Χριστῷ, en Christōi). Paul uses this phrase over seventy times throughout his letters and it describes Christ as the locus of believers’ existence. They have their being in the realm that is filled with and marked by the crucified and risen Christ.
- In (the realm of) Christ, believers share all things with (σύν syn) Christ. Paul often creatively uses this preposition as a prefix.  It is logical that this is such a common preposition in discussions of participation because that is what koinōnia is at its core: a sharing of everything with Christ and those in Christ.
- Now the faith of Christ is the origin of believers’ existence: they are from the faith of Christ (Rom 3:26; Gal 2:16; cf Rom 4:16; Gal 3:7, 9). Believers live through (διὰ dia) Christ (1 Cor 8:6); they suffer for (hyper) Christ (Phil 1:29), and live in unity in accord with Christ Jesus (κατὰ Χριστὸν Ἰησοῦν kata Christon Jēsoun; Rom 15:5).
Finally, Paul uses metaphors when talking about union with Christ, such as adoption into the family of Christ. This will be the focus of later articles.
2. Theological Terminology
‘Union’ is actually one word among others that theologians use to get at this concept. Others are:
- Representation — Christ represents us as king
- Incorporation — we are incorporated into (the community of) Christ
- Identification — we identify with Christ
- Participation — we participate in the life and story of Christ
These terms can be integrated if we consider the concept of Messiahship.  As Messiah, Jesus represents his people both in who he is and what he does. His realm overlaps with his people as the renewal of the cosmos still awaits consummation. This means that to be in the realm of Christ’s lordship means to have been incorporated into the people of Christ. As king, Jesus identifies with his people and his people with him in loving loyalty. Lastly, his people participate in his mission, which I will expand on below.
To further elucidate union with Christ, one can lay it out along the following dimensions: 
- Objective — the individual, unique Son of God, crucified and risen in history, present through the Spirit in believers and the church;
- Subjective — the individual believer participating in Christ through the Spirit, adopted as son, co-crucified and co-risen with Christ;
- Intersubjective — the corporate community of believers united to Christ and to each other in death and resurrection with Christ through the Spirit.
First I will discuss the objective dimension (part 3), before connecting this to the subjective and intersubjective dimensions (part 4). Lastly, I will highlight believers’ transformation in Christ from both an anthropological and theological point of view (part 5).
3. The Crucified and Risen Christ
At the heart of Paul’s theology is, indeed, the gospel of the crucified and risen Christ. This constitutes the ‘objective’, historical dimension. Christ was crucified, Christ was resurrected. A short discussion of the meaning of Christ’s work here is necessary.
First of all, one cannot separate the person from the work of Christ. What he does reveals who he is — indeed, who God is, which we will further touch on in part 5.
Secondly, one must see the cross and the resurrection in apocalyptic/eschatological perspective. The cross deals with the present evil age, marked by the guilt of sins and the powers of Sin, Death, evil spiritual beings, the World and the Flesh. This age could be summarised as exile: away from God’s presence, humanity is enslaved and dehumanised, while still being held responsible for its participation in this system of oppression and evil. The resurrection, then, ushers in the blessed age to come, marked by justification, righteousness, the power of the Spirit of life, the rule of the Messiah, the restoration of creation and of individual embodied life (see table 1). This could be seen as the new exodus.
Thirdly, the cross paves the way for the resurrection. The present age must be dealt with in order for the age to come to arrive, and the way Christ does so is often called the ‘atonement’. There are various ways of talking about the atonement, but an important one is through the notion of sacrifice: Christ died for us. In love he took on himself the fate of Israel and of the world, which is exile. The judgment Israel deserved, and with it the world, fell on Jesus.  Paradoxically, this became the way to the resurrection. Death led to life; exile brought about exodus.
Christ was faithful to God and his God-given mission in loving others till death.
Fourthly, the cross not only leads to the resurrection but also defines resurrection life. The cross was both an act of faith(fulness) toward God and love toward human beings.  Christ was faithful to God and his God-given mission in loving others till death (Rom 3:21–26; Gal 2:15–21; Phil 2:5–11; 3:9) — not just others, but his very enemies (Rom 5:6–11). Moreover, the resurrected Christ remains the crucified Christ, which means that, to use Gorman’s terms, resurrection life is cruciform, namely, marked by faith and love. Although there will not be suffering in the age to come, there will be cruciformity.
Fifthly, the resurrection validates the crucifixion: the crucified Messiah is the real Messiah. The one condemned by the people is justified by God as the eschatological ‘king of the Jews’ (Rom 1:4; cf. 1 Tim 3:16). By raising him from the dead, God confirms that the crucified Jesus is really the locus of the people of God in the promised age to come. 
Sixthly, the resurrection empowers cruciformity in the overlap of the ages. Although the resurrection inaugurated the age to come, we still await its consummation at Jesus’ second coming. This is the ‘already-not-yet’ dimension of New Testament eschatology. In the overlap of the ages, believers are empowered by the resurrection to suffer with Christ in faithfulness to God, in love for others, and in hope of the coming glory and the resurrection of the body (thus completing the triad of faith, love, and hope). But now I’m getting ahead of myself.
4. Individual and Corporate Participation through Pistis and Pneuma
The gospel of the crucified and resurrected Messiah does not remain objective. The crucified and resurrected Christ is living and present in the church through faith and through the Spirit. These two are integrated, even inseparable, realities: faith receives the Spirit, and the Spirit produces faith. On the one hand, the Spirit is given by God upon faith; on the other hand, the Spirit is poured into the human heart and produces faith. We might capture this double tension by saying that faith is how the Spirit makes his entry. 
Faith unites Christ and believers narratively and missionally: through faith, believers participate in the cross-and-resurrection story of Jesus. Through participation in the cross, they are liberated from the powers of the present age (see above; cf. Gal 2:15–21). Through participating in the resurrection, they are vindicated by the Father and begin a new life for God through the Spirit (cf. Rom 6:10–11).
Now, being both reconciled, liberated and transformed ‘in Christ’, believers progressively embody and live out Christ’s faithfulness. This pistis consists of faithfulness toward God which is active in love toward others (Gal 5:6; cf 5:22), both neighbour (or, as Paul would say, ‘brother’) and enemy. Thus believers continue Christ’s mission of the kingdom, even, or especially, amid suffering. This is what Paul gets at when he says that he ‘bears the scars of Christ’ (Gal 6:17) and ‘fills up what is still lacking in the afflictions of Christ’ (Col 1:24). 
Faith is therefore based on the objective work of Christ but goes beyond that in participating in that work. It is both cruciform — that is, ‘faith working through love’ — and resurrectional — that is, empowered by the life-giving Spirit and leading to new experiences of life, both for self and others.
The Spirit, then, unites Christ and believers existentially or mystically: the Spirit is the Spirit of Christ (Rom 8:9; Gal 4:6; Phil 1:19) and ‘the Spirit of him who raised Jesus from the dead’, indeed, the very glory and power of God (cf. Rom 6:4; 1 Cor 6:14). This is what systematic theologians call inseparable operations: where the Spirit is at work, so are the Father and Son, and vice versa. Thus, also Christ is said to live in believers (Rom 8:10; 2 Cor 13:5; Eph 3:17; Col 1:27), while the presence of the Father can be deduced (cf. 1 Thes 1:1; 2 Thes 1:1). (The latter is a Johannine notion; see Joh 14:23; 1 Joh 4:4, 15–16; cf Joh 10:30).
So, not only are believers in Christ, Christ is also in believers (mutual indwelling). Precisely because they are indwelt by the Spirit of the Son, believers are conformed to the person and story of the Son. Christ’s thoughts become their thoughts (1 Cor 2:16; cf Rom 8:5–7; 12:1; Eph 4:23), Christ’s affections become their affections (Phil 1:8; cf 2:1, 5), and Christ’s practices become their practices (e.g., Phil 2:3–11). This conformity is not just imitation; believers actually embody and enact Christ’s faith. Believers are Christ-agents because Christ works in and through them through his indwelling Spirit.
Therefore, while faith concerns the work of Christ and believers, the Spirit entails the person of Christ and believers. To use philosophical terms, the first is functional, the second ontological.  Faith and the Spirit come together in the corporate, participatory rites of baptism and the Lord’s Supper, but I must leave those very promising topics for future articles.
5. Transformation: Wholeness and Theosis
Therefore, both missionally and mystically, believers are united with the Son of God and, in this union, are transformed through the Spirit. This transformation in Christ can be approached from two angles. Working from the concepts of the image of God and the incarnation, Jesus is the archetypical (new) Human, the new Adam who represents the new humanity, the new Messianic philosopher-king who represents the new Israel. He embodies human faithfulness to the covenant and the covenant God in loving others, thus showing what it means to be human. Therefore, as believers come to share more and more in Christ, they become more human.
Secondly, considered from the perspective of the Trinity and the hypostatic union, Jesus is the self-revelation of God. He does not just show who God is as a mirror, but as a veil. He embodies God’s covenant faithfulness and love for Israel and the world, not merely as an agent of God but as God himself.  As Paul says in Colossians 2: “For in Christ all the fullness [plērōma] of the Deity lives in bodily form” (Col 2:9). Paul then connects believers with this Christ-full-of-Deity: “and in Christ you have been filled [peplērōmenoi]” (cf. Eph 1:23; 3:16–17, 19). This mind-blowing statement means that in the embodied forms of individual and corporate Christ-life, the fullness of who God is, is present. Believers are filled to the brim with God-ness. Because God is in Christ, and we are in Christ, God is in us.
Thus, in union with Christ, believers do not merely become whole as human beings, but they do so as they participate more and more in God-ness. This process is historically called theosis.  At the center of this all is the image, the ikōn, of the crucified and resurrected Christ. To be like him is to be like God, and to be like God is to be cruciform.
 Cf. the recent work on Paul by Douglas J. Moo, A Theology of Paul and His Letters. See also Michael J. Gorman, Participating in Christ: Explorations in Paul’s Theology and Spirituality.
 Rom 12:13; 15:26, 27; 1 Cor 1:9; 10:16, 18, 20; 2 Cor 1:7; 8:4, 23; 9:13; 13:14; Gal 2:9; 6:6; Phil 1:5; 2:1; 3:10; 4:15; Phm 1:6, 17. The relative importance of these terms in Philippians and Philemon is significant.
 For example, in Romans 6, Paul coins the terms συσταυρόω (systauroō, ‘co-crucify’; 6:6), συνθάπτω (synthaptō, ‘co-bury’; 6:4) and συζάω (syzaō, ‘co-live’; 6:8). Moreover, in Romans 8, Paul talks about being ‘co-heirs’ (συγκληρονόμοι sygklēronomoi), ‘co-suffering’ (συμπάσχω sympaschō) and being ‘co-glorified’ (συνδοξάζω syndoxazō).
 See the magnificent section on Christology in N.T. Wright, Paul and the Faithfulness of God, ch. 9.
 See Constantine R. Campbell, Paul and Union with Christ: An Exegetical and Theological Study, and the collection of essays edited by Thate, Vanhoozer and Campbell, ‘In Christ’ in Paul: Explorations in Paul’s Theology of Union and Participation.
 Cf. Wright, Paul and the Faithfulness of God, 825: ‘Jesus, a Messiah, has drawn together the identity and vocation of Israel upon himself’ (italics original). Wright also wrote about this connection in Jesus and the Victory of God in very helpful ways.
 Gorman has argued this extensively throughout his works; see especially the section ‘Christ’s Death as the Quintessential Covenantal Act’ in Inhabiting the Cruciform God: Kenosis, Justification, and Theosis in Paul’s Theology, ch. 2.
 See the final chapters of N.T. Wright, The Resurrection of the Son of God.
 This is the same (paradoxical) relationship as between cross and resurrection: cruciformity leads to experiences of life (in the Spirit), while the (Spirit of the) resurrection empowers cruciformity (= faith).
 This does not mean that Paul is reconciling himself or liberating himself. Rather, he is experiencing and embodying this very reconciliation and liberation of God and thus becomes an agent of that reconcilation and liberation. If non-believers would see Paul in his faith and love even amid suffering, they would see a walking and breathing image of Christ. In other words, they would see cruciformity and Christoformity. Cf. Gorman, Becoming the Gospel: Paul, Participation, and Mission.
 This does not mean at any point that the lines between God’s being and believers’ being are blurred. At no point does God become believer or believer become God in such a way that their existences merge. However, as Calvin argues in his Institutes, this is a union (as intimate as it is!) not of natures but of persons, as in the communion of marriage (cf Gen 2:24 and Eph 5:30–1).
 See N.T. Wright, Jesus and the Victory of God, ch. 13.
 See Gorman, Cruciformity (2021), in the afterword: ‘To be cruciform is to be Christlike, which is to be both more like God and more fully human.’ See also his Inhabiting the Cruciform God and Participation in Christ.