Interpenetration Logic: Pauline Spirituality and Union with Christ

Abstract

While definitions of spirituality vary, each contains elements of union, a coming together of humanity and divinity. Scholars agree on the centrality of “union with Christ” in Pauline thought, yet not on a definition of union. Ephesians 5:31–32, however, provides important insight through a quotation—“…the two will become one flesh” (Genesis 2:24)—and an explanation—“I say this with reference to Christ and the church”. While scholars highlight the preservation of distinct identities, Paul’s emphasis in the marriage metaphor, both here and elsewhere, is union, an interpenetration logic where two become one. Indeed, interpenetration logic is present in our union with Christ (Galatians 2:19–20) and our union with sin (Romans 7:9–25). Both unions harness the same two-become-one logic with drastically different ends: sin intends to obliterate (Rom. 3:23); Christ intends to resurrect (1 Corinthians 15:22). The crux of Pauline spirituality, then, is not ecstatic experiences or ethical imitations but union—reciprocal residence, where we are in Christ and Christ is in us; a mutual indwelling consummated by “the Spirit of life” (Rom. 8:2). Thus, Eph. 5:31–32 provides insight into interpenetration logic, where two become one without the obliteration of either. This is an insight that profits our understanding of Pauline spirituality and the “profound mystery” of union with Christ.

1. Introduction

A brief survey reveals a wide variety of definitions for Christian spirituality.1 This is not due to confusion, however, but to the profundity of spirituality, to its innate mystery occupied by spiritual practices, mystical experiences, and the life birthed through encounters with that which, by definition, is beyond our senses, even as it overwhelms them. Some denotations rely on the etymology of spirituality as a guide, defining it as life “according to the Spirit of God rather than according to a ‘worldly’ spirit” (Sheldrake 2016, pp. 21–22). Others offer ambiguity to tame the mystery, rendering spirituality as “nothing less than an invasion of natural human reality by a supernatural life ‘from below’” (Willard 2002, p. 18). Yet, as Leslie Hardin argues, all definitions of spirituality—Christian or otherwise—wrestle with “the tension between experience and praxis” (Hardin 2015, p. 134),2 between an encounter with the divine and its ramifications expressed in the life lived thereafter.3 Assumed in these definitions, regardless of which end of the spectrum one begins or ends, is a common thread of “union”, a coming together of humanity and divinity. Union: a topic saturating while confounding Pauline scholarship since before E. P. Sanders and into the modern-day.4

E. P. Sanders situated “participation with Christ” at the heart of Pauline theology, stressing that Paul’s “basic insight was that the believer becomes one with Christ Jesus”, and that “one participates in salvation by becoming one person with Christ” (Sanders 1977, p. 549). Yet elsewhere, after affirming that in Paul “Christians really are one body and Spirit with Christ…being changed from one stage of glory to another”, Sanders ends with this oft-quoted perplexity: “But what does this mean? How are we to understand it?” (Sanders 1977, p. 522). With a humility often absent on any level of scholarship, Sanders concedes, “I must confess that I do not have a new category of perception to propose here. This does not mean, however, that Paul did not have one” (Sanders 1977, p. 523).

Sanders’s conundrum propelled pursuits and projects in Pauline scholarship thereafter. Richard Hays guardedly suggests the answer could be found through “careful study of participation motifs in patristic theology, particular the thought of the Eastern Fathers” (Hays [1983] 2002, p. xxxii), a suggestion pursued in a variety of projects by Michael Gorman.5 Others, however, uncomfortable with prominent Eastern categories such as theosis, restrict their exploration, for the most part, to the New Testament (so Macaskill 2013), climaxing with Constantine Campbell’s classification of Paul’s “union with Christ”, codified by his four-fold “umbrella concepts”: [1] union, [2] participation, [3] identification, and [4] incorporation (C. Campbell 2012, p. 413).

Each project contributes insights and nuances to the ever-elusive definition of “union with Christ”, employing terminology new and old to nurture the conversation ever-forward.6 Still, key prepositions (and their corresponding prepositional phrases) typically orient the exploration in the phraseology of Paul himself. Chief among these Pauline phrases is “in Christ” (ἐν Χριστῷ), used seventy-three times in the Pauline corpus (compared to three times in the rest of the New Testament).7 Additionally, comparable phrases—for example, “with Christ” (articulated by σὺν Χριστῷ or merely the συν– prefix), “Christ in us”, etc.—balloon the number of references to well over one-hundred and fifty.8 Unsurprisingly, then, union with Christ has rightly been identified as “the ‘webbing’ that holds [Paul’s thought] all together”, in that “virtually every topic that Paul addresses is in some measure connected to union with Christ” (C. Campbell 2012, p. 441).9 Or, as Michael Gorman resolves, “Participation is not merely one aspect of Pauline theology and spirituality, or a supplement to something more fundamental; rather, it is at the very heart of Paul’s thinking and living” (Gorman 2019, p. xviii).10

Thus, any discussion of Jesus and spirituality in Paul must engage union—this central category of Pauline thought already assumed, whether knowingly or not, in definitions of spirituality, regarding Paul or otherwise. The problem is that scholarly consensus on the centrality of “union in/with Christ” has not dispelled the mystery of this union that confounded E. P. Sanders decades prior. The wide array of approaches and attempts in Pauline scholarship over the first few decades of the 21st century seem to confirm Michel Bouttier’s exasperation in the middle of the previous century, “Comment imaginer aboutir ici à une solution définitive?” (Bouttier 1962, p. 22).11 Thus, while union with Christ (or the mystery of “in Christ”) is central to Paul, its definition proves elusive.

While further exploration of the Early Patristics and the Eastern Fathers is to be encouraged (i.e., Hays [1983] 2002, p. xxxii),12 the disputed letters in the Pauline corpus (namely Ephesians) may yet contain a clue for how union is to be understood, engaged, and utilized to discover and articulate union (both with Christ and others) in the undisputed letters of Paul, thereby shedding light not only on sacraments, Pauline metaphors (e.g., the Body of Christ), and humanity’s relationship with sin, but also on a Pauline definition of spirituality “in Christ”.13

2. A Profound Mystery: Ephesians 5:31–32

In the middle of the Ephesian household code (5:21–6:9), just after instruction for husbands and wives (5:21–30) and just before counsel for children and parents (6:1–4) and slaves and masters (6:5–9), Paul offers a peculiar quotation (5:31) and a shocking explanation (5:32):

“For this reason man will leave behind father and mother and will be united to (προσκολληθήσεται) his wife, and the two will become one flesh” (Gen. 2:24). This is a profound mystery (μυστήριον): but I say this with reference to Christ and the church.14

Matrimonial metaphors are not unique to Eph. 5:31–32, although they are not common in the Pauline corpus, only appearing on four occasions: Rom. 7:1–4; 1 Cor. 6:15–17; 2 Cor. 11:2–3; Eph. 5:22–32.15 Yet, the intimacy of the Genesis 2:24 quotation, intimating sexual union, offers a startling context when applied to Christ and the church.

Indeed, the metaphor should not be reduced to crass eroticism, where what is envisioned is sex with a deity, an image more fit for cults of Cybele than Christ and his bride. Nevertheless, the metaphor cannot be completely expunged of the sexual inference, nor should it be. In the physical realm, sexual intimacy is the climax of union between two separate yet interpenetrating persons—unmatched by any other act in creation—and contains overtures of life and creation absent in other acts of union between two bodies, such as, for example, holding hands, hugging, or even kissing. The sexual element of the metaphor calls attention to a logic of union essential to the relationship of Christ and his church. Eph. 5:31–32 invokes a union that certainly surpasses mere physical interpenetration, but it cannot be fully comprehended without it.

This may partially explain the brevity with which interpreters engage the marriage metaphor, or at times, overlook it entirely.16 Other metaphors like the “body of Christ” appear far more safe for discussions of union, if at least more prudent. To be fair, Paul’s infrequency of the marriage metaphor must contribute to its neglect, but even when it is engaged, the scholarly emphasis is almost uniformly on the preservation of “distinctive identities of Christ and church…avoiding unhelpful theories of union in which identities are blurred” (C. Campbell 2014, p. 67).17 Oddly, then, scholars employ the marriage metaphor to emphasize the separation of two parties, which is the opposite of Paul’s emphasis. Although distinction is included in the metaphor, Paul introduces the imagery of marriage, with its sexual implications intact, to stress the “profound mystery” of union, where two become one, especially in Eph. 5:31–32.

Throughout the Pauline corpus, references to “mystery” (μυστήριον), found here in Eph. 5:32, contain a thread of union, an interpenetration of two seemingly opposite entities brought together through the salvific work of God. So, Paul proclaims “the mystery (μυστήριον) of God” by preaching only “Jesus Christ and him crucified” (1 Cor. 2:1), an event that oddly conjoins the “foolishness (μωρία)” of the cross and the “power (δύναμις) of God” (1:18).18 Elsewhere Paul celebrates Christ’s salvific work, a “mystery (μυστήριον)” revealed to “the saints of God” (Eph. 1:9; 1:1), through which he “brought to unity all things in Christ, things in the heavens and things on the earth” (1:10),19 including, and perhaps most shocking to much of Paul’s audience, the interpenetration of Jew and Gentile in the church wed to Christ (Eph. 3:1–6).20 The mystery of God’s salvific work is rooted in union of the incomprehensible, where even mortality and immortality unite as one (1 Cor. 15:51–54). Or, as Paul summarizes in Colossians 1:27, “the rich splendor of this mystery (μυστήριον), which is Christ in you (Χριστὸς ἐν ὑμῖν)—the hope of the splendor”.21

The context preceding the “profound mystery” of Eph. 5:31–32 also promotes this priority of union. Ephesians 4 begins with the call to diligently “keep the unity of the Spirit” (4:3), reminding the Christians of the centrality of union with the recurrent use of “one”: “There is one body and one Spirit, just as you also were called into one hope…. There is one Lord, one faith, one baptism, one God and Father of all” (4:4–6a).22 In 4:11–16, Christ gifts the church with “the apostles, the prophets, the evangelists, the shepherds and teachers” (4:11) for the purpose of building up the body of Christ “until all of us attain unity of the faith” (4:13)—“the whole body being joined together and united together by every binding ligament of support” (4:16). In contrast, those “alienated from the life of God” (4:18) are self-serving, filled with greed (4:19) and a proclivity toward words and deeds that do not build others up (4:22, 28–31; 5:3–6). However, as “children of light” (5:9), we partner with the Spirit (4:30; 5:18) to rid ourselves of “all bitterness and rage and anger and yelling and injurious speech” (4:31) in exchange for being “kind and compassionate toward one another, forgiving each other just as God in Christ also forgave you” (4:32); for “we are members of one another” (4:25)—interpenetrated with each other in the same way that “everything illuminated [by light] is light” (5:14a). Indeed, we were once “darkness, but now light in the Lord” (5:8a), united with Christ’s victory over death (5:14).

Thus, the invocation of a “profound mystery (μυστήριον)” and the preceding context firmly secure Eph. 5:31–32 in a context centered on union—not distinction.23 Similarly, to reduce the metaphor down to mere sexual intercourse misses Paul’s point entirely, for this revelation is “a profound mystery” that rests beyond the physical, even while harnessing it to explore the metaphysical. Indeed, the quotation of Genesis 2:24 invokes a principle or logic of interpenetration woven into prelapsarian creation, unaffected by its misappropriation in the Fall, but now, in Christ, reoriented for union with humanity—where two become one.24

3. Made for Union: For Better, for Worse

Susan Grove Eastman’s important work, Paul and the Person: Reframing Paul’s Anthropology,25 provides greater context for anthropological discussions of union. Spanning an impressive array of disciplines, Eastman harnesses trajectories of “the self” in ancient philosophy and modern developmental psychology, among others, and articulates a model of self that is both ancient and modern: “the self-in-relationship”. From this study, she reasons:

[The self] is intersubjective all the way down. The Cartesian idea of an individual, freestanding, independent self is long gone. There are no lone rangers on this playing field; for good or for ill, there are always other players involved.

(Eastman 2017, p. 79)26

In other words, humanity was created not just with the capacity for union with another but with the essential necessity of interpenetration: “the self is never on its own but always socially and cosmically constructed in relationship to external realities that operate internally as well” (Eastman 2017, p. 8). Thus, after exegetical analysis of the undisputed letters of Paul,27 Eastman offers this insightful conclusion: “[Paul] displays a functional understanding of human beings as relationally constituted agents who are both embodied and embedded in their world….There is no freestanding ‘self’ in Paul’s cosmos….Rather, Paul’s anthropology is participatory all the way down” (Eastman 2017, pp. 2, 9).

The principle and logic of the self-in-union paradigm extends beyond (while it includes) interpenetration between humans. Whether in the ancient philosophy of Epictetus (Eastman 2017, p. 48) or in the ancient account of Genesis, humanity also exists in union with “suprahuman realities” (Eastman 2017, p. 91). As Eastman argues, “embodied human existence is always embedded in, and qualified by, supracorporeal forces, whether those be merely human social realities or cosmic powers” (Eastman 2017, p. 91).

A cursory survey of Genesis 1–3 exhibits this elaborate interplay of union, both corporeal and incorporeal, both good and evil. Humanity is interpenetrated with the image of God in creation (Gen. 1:26–27), even while shaped from the “dust of the earth”, sharing substance with the created ground itself (2:5–7). God placed man in the Garden of Eden (2:15) and pronounced: “It is not good for man to be alone” (2:18), for man was made for union. Thus, a deep slumber led to another unique moment of union, for like the “dust of the earth”, woman is created from man’s flesh (2:21–22), celebrated in a hymn-like ode to union:

The man said,

• “This is now bone of my bones
• and flesh of my flesh;
• she shall be called ‘woman,’
• for she was taken out of man”.
(2:23, NIV)

Just before the scene closes in chapter two and the tragedy of chapter three unfolds, Genesis lauds a profound mystery: “That is why a man leaves his father and mother and is united to his wife, and they become one flesh” (2:24, NIV). Genesis 3, however, does not discontinue the theme of union; it recounts humanity’s choice to interpenetrate with sin and death through ingesting the flesh of the fruit from the tree of the knowledge of good and evil (3:1–7)—a type of “anti-communion;” a union with another—albeit cosmic and evil, nevertheless still just as penetrating as all the previous.

Interpenetration logic, therefore, offers clarity not only for our union with Christ but also our relationship with sin. As many Pauline scholars have noted, Paul, in more than one instance, portrays sin as an active agent in the present age, prompting many to reflect this by translating “sin” as “Sin”.28 This is not, however, simply a literary device deployed for dramatic effect. “Sin”, Matthew Croasmun corrects, “is a substantive being—this is no matter of ‘mere personification’ or ‘mere metaphor’” (Croasmun 2014, p. 147). Indeed, throughout Romans 5–7, Paul applies attributes and actions to Sin typically reserved for human beings or God himself (Eastman 2017, p. 113).29 Sin comes to life (Rom. 7:9; cf. 5:12, 13), fit with a body (6:6—σῶμα τῆς ἁμαρτίας)30 and desires (6:12b; 7:5), prepared to deceive (7:11) and to seize any opportunity to advance its agenda (7:8, 11). Sin reigns sovereign (5:21a; 6:6a; 12), wielding its own “law” (7:23, 25b), which governs the acts and thoughts of those enslaved or incarcerated by Sin’s dominion (6:6b-7, 14a, 16–18, 20, 22; 7:14, 17, 20, 23, 25b). Sin even indwells humanity in ways comparable to Christ living in us: “But now, I myself no longer do it, but Sin living inside me” (Rom. 7:17; cf. Gal. 2:20).31

Thus, Sin is “not just a thing we do but a power that rules and controls” (Macaskill 2019, p. 106). Sin is an active agent, a being with substance, an entity with a will, a rationality, an intentionality, an agenda, and a purpose, ever-lurking and “crouching at your door” (Gen. 4:7), longing to ensnare and to dominate humanity. As such, humanity is capable of union with Sin as it is with other humans and supracorporeal beings—an interpenetration following a two-become-one logic. So, in Genesis 3 and even today, humanity, indeed, becomes one flesh with Sin.

The human body (σῶμα), then, as Ernst Käsemann remarks, “is contested territory in the battle between cosmic powers” (Käsemann [1969] 1996, p. 20),32 a battleground of competing unions that each transform “what we are”33 and therefore how we act. Additionally, the interpenetration logic invoked in Eph. 5:31–32 explains Paul’s exasperation at the sexual immorality present in the church in 1 Corinthians 6:13–17. In 6:13, Paul advocates for the body’s (σῶμα) union with “the Lord” against the union wrought through “sex with a prostitute (πορνείᾳ)”.34 Agitated at the thought, in 6:15, Paul exerts his characteristic μὴ γένοιτο, “Do you not know that your bodies (σώματα) are members of Christ? Shall I then take away the members of Christ and make them members of a prostitute (πόρνης)? By no means!” Paul elucidates his objection further by emphatically articulating the two-become-one logic found in Genesis 2:24: “Do you not know that the one who is united (κολλώμενος) to the prostitute is one body (σῶμά) with her? For it says, ‘The two will become one flesh’” (6:16). The same logic and quotation applied to Christ and the church in Eph. 5:31–32 is now applied to the sexual union with a prostitute because in the immoral act a competing union is embraced, forgetting or, worse, rejecting the truth that “the one who is united (κολλώμενος) to the Lord is one Spirit with him” (6:17).35 Indeed, the body houses a cosmic battle that extends beyond the physical while directly affected by the physical.36

Humanity is made for union with another, be it human or suprahuman, an individual or a corporate body. Certainly, the interpenetration logic elucidated in 1 Corinthians 6:13–17 is a precursor for the same principle of union invoked in 1 Corinthians 10:14–21 to contrast the union of demons and idols with the Lord’s Supper and the body of Christ,37 for “you are not able to drink the cup of the Lord and the cup of demons; you are not able to eat at the table of the Lord and the table of demons” (10:21). The act of ingesting, as in Genesis 3, is an act of union where two become one, yet our actions dictate with whom we unite—good or evil, Christ or Sin, for better or for worse.38

4. Same Logic, Different Telos

While humanity, to varying degrees, unites with both Christ and Sin through interpenetration logic, the telos of each union is drastically different. Sin intends to obliterate; Christ intends to resurrect. Sin oppresses and suppresses the individual, persistently attempting to override one’s will, comparable to a demonic possession. Christ empowers and unfolds the gifts and potentialities buried in the individual, stubbornly refusing to ignore one’s will, comparable to the perichoretic relationship of the Trinity itself. Each union is ontologically pervasive, yet with consequences as different as light and darkness.

As Sin interpenetrates, a struggle ensues: “sin and the self are locked in a competitive embrace, and sin has the upper hand” (Eastman 2017, p. 122). Sin dominates, intimidates, imprisons, and suppresses its subject like “a hostile colonizing power” (Eastman 2017, p. 109). This union, ironically, results in a divorce from others and even from the self itself, producing a disorienting combination of internal and external turbulence:

For I do not understand my own actions. For I do not do what I want, but I do the very thing I hate…I have the desire to do what is right, but not the ability to carry it out. For I do not do the good I want, but the evil I do not want is what I keep on doing. Now if I do what I do not want, it is no longer I (οὐκέτι ἐγὼ) who do it, but sin that dwells in me (ἀλλὰ ἡ οἰκοῦσα ἐν ἐμοὶ ἁμαρτία).

(Rom. 7:15, 18b-20, ESV)

Sin attempts to annihilate the subject, assaulting one’s mind and will to manipulate one’s actions. Like a parasite, Sin siphons the life from its host. Sin pervades the subject to fully possess the self, rendering the person as less than human—as if the subject no longer lives, but only the Sin inside.

Tension surfaces, however, when similar language is used by Paul to describe his union with Christ: “I have been crucified with Christ, and it is no longer I (οὐκέτι ἐγώ) who live, but Christ who lives in me (ζῇ δὲ ἐν ἐμοὶ Χριστός)” (Gal. 2:19b–20a). Indeed, this passage is not periphery, for as Grant Macaskill insists, “all talk of the Christian moral life must begin and end with Paul’s statement ‘It is no longer I who live, but Christ who lives in me’ (Gal. 2:20)” (Macaskill 2019, p. 1). Thus, any discussion of union with Christ and its implications for spirituality must answer the question, “Does union with Christ result in the obliteration of the self?”

Certainly, some scholars advocate for a union in Christ that, to some degree, results in the annihilation of the individual,39 chief among them being Albert Schweitzer, whose articulation is worth quoting at length:

The concept of being-in-Christ dominates Paul’s thought in a way that he not only sees in it the source of everything connected with redemption, but describes all the experiences, feeling, thought and will of the baptized as taking place in Christ. Thus the phrase “in Christ Jesus” comes to be added to the most varied statements, almost as a kind of formula…. [Yet] it is no mere formula for Paul. For him every manifestation of the life of the baptized man is conditioned by his being in Christ. Grafted into the corporeity of Christ, he loses his creatively individual existence and his natural personality. Henceforth he is only a form of manifestation of the personality of Jesus Christ, which dominates that corporeity. Paul says this with trenchant clearness when he writes, in the Epistle to the Galatians, “I am crucified with Christ, so I live no longer as I myself; rather, it is Christ who lives in me” (Gal. ii. 19–20).

(Schweitzer [1930] 1998, pp. 124–25)

In response, many scholars, understandably, obsess over distinctions between the Creator and the creature in any discourse on union with Christ or “in Christ”.40 Fearing the obliteration of the individual, marriage metaphors and language like “the two become one flesh” found in Eph. 5:31–32 are altered from emphasizing union to distinction. Yet this is only necessary if we understand union with Christ and Galatians 2:19–20 through the telos of union with Sin: the annihilation of the individual.

As others have noted, even after union with Christ in Galatians 2:19–20, Paul still exists as a recognizable individual with agency, both in the immediate context (2:20b-21—Parsons (1988), p. 35) and throughout the entire letter.41 Yet something discernible in Paul has so significantly shifted that “crucifixion” and “no longer lives” are not only appropriate but essential to describe his new existence “in Christ”. For, indeed, who Paul is in Christ—his very identity and ontology—is no longer who Paul was before Christ. “Paul”, as Macaskill summarizes, “is now Paul-in-Christ; Paul-in-himself is a thing of the past. We might even translate Gal. 2:20 as ‘I live, yet not I, but Christ lives in me” (Macaskill 2019, p. 53). Thus, what is executed when Paul is “crucified with Christ” is not Paul’s person, thereby obliterating Paul’s existence absorbed into Christ. Instead, Paul’s one-flesh-with-Sin is assaulted, his “body of Sin (σῶμα τῆς ἁμαρτίας)” (Rom. 6:6) crucified,42 so that “what no longer lives” is Paul-interpenetrated-with-Sin that oppresses and suppresses his person with the goal of annihilating Paul altogether. Now, Paul exists as Paul-in-Christ-and-Christ-in-Paul, a reciprocal residency free from competition and characterized by a mutual “not my will but yours be done”.43 Far from the dissolution of the person, “Galatians 2:19–20 depicts a gracious divine-human mutual indwelling that transforms the self in the midst of daily life…[and] discloses and requires an intersubjective picture of the person all the way down” (Eastman 2017, p. 163).44

Once again, the marriage metaphor in Eph. 5:31–32, imbued with sexual intimations, brings lucidity to union in Christ. Pregnancy—to borrow an image from Galatians 4:19—is appropriately understood as “an intersubjective picture” of two-persons-as-one, the child indwelling the womb of the mother. The telos is not obliteration of one person or the other, but an interpenetration of two distinct persons as one with the end goal being life to the full. To shift the metaphor yet again, this is precisely how Paul envisions the church when he describes them as the body of Christ:

For just as, indeed, the body (σῶμα) is one and has many members, but all the many members of the body (σὠματος) are one body (σῶμα), so also is Christ. For in one Spirit we were all baptized into one body (σῶμα)—whether Jews or Greeks, whether slaves or free—and all were made to drink one Spirit. For the body (σῶμα) is not one member but many.

(1 Cor. 12:12–14)

Being a part of the church does not result in the loss of the self, but an interpenetration of persons as one body, a reciprocal residency free from competition and characterized by a mutual care and concern for the life of the other (12:15–26).45

Thus, while union with both Sin and Christ follows an interpenetrating logic, each union contains a distinct telos. Sin induces death (Rom. 3:23); Christ induces life (1 Cor. 15:22):46 a life, that is, interpenetrated with the Spirit of life (Rom. 8:2).

5. The Spirit of Spirituality

Spirituality in Paul, then, is not centered on ecstatic experience or moral living, even though both are present (e.g., 2 Cor. 12:1–10; 1 Thess. 4:1–8). The crux of Pauline spirituality is union: reciprocal residence, where we are in Christ and Christ is in us—a mutual indwelling consummated by “the Spirit who gives life” (Rom. 8:2, NIV).

Romans 8, in many ways, is the climax of the discourse on union with Sin that precedes it. The despair of Romans 7:24—“Wretched man that I am! Who will rescue me from this body of death (σώματος τοῦ θανάτου)?”—is replaced by the doxology of Romans 7:25—“But thanks be to God through Jesus Christ our Lord!”—before bleeding into the declaration of Romans 8:1–2: “So then, now there is no condemnation for those who are in Christ Jesus (ἐν Χριστῷ Ἰησοῦ). For the law of the Spirit of life in Christ Jesus (ἐν Χριστῷ Ἰησοῦ) has set you free”. This is not a mere transfer of status, for what follows centers on the rebirth of the children of God through the movement of the Spirit dwelling within:

But you are not in the flesh47 but in the Spirit, if indeed the Spirit of God dwells in you (οἰκεῖ ἐν ὑμῖν).48 But anyone who does not have the Spirit of Christ does not belong to him. But if Christ is in you (Χριστὸς ἐν ὑμῖν), though the body (σῶμα) is dead through Sin, the Spirit is life through righteousness. And if the Spirit of the one who raised Jesus from the dead dwells in you (οἰκεῖ ἐν ὑμῖν), the one who raised Christ from the dead will also give life to your mortal bodies (θνητὰ σώματα) through his Spirit dwelling in you (ἐνοικοῦντος αὐτοῦ πνεύματος ἐν ὑμῖν).

(Rom. 8:9–11)

The Spirit, like Christ, actively dwells in the child of God, resurrecting her into a life lived in, through, and with the Spirit (2 Cor. 3:18; 5:17).

Yet, as Romans 8:9–11 indicates and Romans 7:15–24 illustrates, the Spirit indwells the body that is one-flesh-with-Sin, resulting in a struggle not just at the level of behavior but at the level of ontology—our “being” and its “constituent elements” (Macaskill 2014, p. 87). Our logic, thoughts, desires, passions, and even interpretations are embattled by Sin’s interpenetration, obscuring God, one another, and even union’s telos: “Those who live according to the flesh have their minds set (φρονοῦσιν) on what the flesh desires … the mind governed (φρόνημα) by the flesh is hostile to God; it does not submit to God’s law, nor can it do so” (Rom. 8:5a, 7, NIV).49 Toward this concern, Paul repeatedly accentuates the importance of renewing our minds (e.g., Rom. 12:2; Phil. 2:1–5),50 for reorienting the mind with “the things of the Spirit” (Rom. 8:5b) alters our volition (Gal. 5:16–25) and animates our actions in a life lived “according to the Spirit” (Rom. 8:4b, 12–13). Thus, indwelled by the Spirit, we experience an “ontological conversion from the flesh to the new creation” (Eastman 2017, p. 181)51—for the solution must be as pervasive, if not more so, than the problem.

Spirituality in Paul, therefore, is not concentrated on pursuing virtues or imitating ethics, but on union with Christ through the Spirit of life. Such a union produces virtue and right living, but these are fruit birthed from this two-become-one logic—an interpenetration free from competition and impregnated with life. Therefore, acts of spirituality (e.g., prayer, confession, etc.) are best understood as movements of union, a choice to cry out “not my will but yours be done” (Mk. 10:36b) that grants an ever-increasing depth of mutual indwelling: Christ in us and us in Christ. Acts of spirituality nurture this reciprocal residence, this profound mystery that translates our prayers into the language of God (Rom. 8:26), uniting our will with the will of the Father (8:27) and the words of his Son: “Abba, Father” (Rom. 8:15; Mk. 10:36).

6. Conclusions

Eph. 5:31–32, therefore, provides an insight from the disputed letters of Paul into the profound mystery of interpenetration logic, where two-become-one without the obliteration of either. Christ’s incarnate union hidden by Sin’s blinding union obscures not only E. P. Sanders’s ability to perceive Paul’s category of participation (Sanders 1977, p. 523), but our ability to conceive of union with Christ without annihilation, to understand our spirituality as more than experience or imitation. The mystical marriage metaphor illuminates the words of Paul from Galatians 2:19–20 to 1 Corinthians 12:12–26 to Romans 5–7 through the light of the Spirit brilliantly ablaze in Romans 8. In sum, following the muse of Richard Hays, I conclude by turning my gaze to “patristic theology, particular the thought of the Eastern Fathers” (Hays [1983] 2002, p. xxxii) and specifically the words of Maximus the Confessor:

…the great Apostle [Paul] clearly bears witness to [the mystery of Christ] when he says that “the mystery hidden from the ages and the generations has now been manifested” [Col. 1:26], identifying the “mystery of Christ” with “Christ” Himself. This mystery is obviously the ineffable and incomprehensible union according to hypostasis of divinity and humanity. This union brings humanity into perfect identity, in every way, with divinity…without creating any diminishment due to the essential difference of the natures. The result, as I said, is that the hypostasis of the two is one, and their natural difference remained inviolate, and thus the quantity of each of the united natures is preserved undiminished even after their union….the natures retained their integrity in every way, neither nature disowning anything properly its own because of the union.

(QThal. 60.2)52