Ephesians 5:31 Commentary: The One-Flesh Union

Paul’s words in Ephesians 5:31 belong to a larger section of the letter where he addresses relationships in a Christian household, wives and husbands, children and parents, slaves and masters. First-century marriage in the Greco-Roman world was deeply patriarchal. A wife moved into her husband’s household, and the husband held legal authority over her. Paul does not simply reinforce that structure. Instead, he uses the Jewish creation account to give marriage a higher foundation. By quoting Genesis 2:24, a verse that both Jews and Gentiles in Ephesus would recognize from the Greek Old Testament, Paul roots marriage not in Roman custom but in God’s original intention. The language of “leaving father and mother” would have been striking in a culture where sons often remained under their father’s authority for life. Paul asserts that marriage creates a new primary bond, one that takes priority even over parents. The phrase “joined to his wife” translates προσκολληθήσεται, a passive verb meaning “will be glued to,” suggesting that God is the one who binds the couple together. In the ancient world, marriage was often a practical arrangement; Paul presents it as a sacred, God-orchestrated union. By placing this quote right after his teaching that husbands should love their wives as Christ loved the church, Paul turns marriage into a living metaphor, the human relationship points to a greater divine reality. The surrounding verses (Eph 5:28, 33) show that the husband’s love and self-giving mirror Christ’s sacrificial love, and the wife’s respect mirrors the church’s response to Christ.

The supplied sources note a minor textual variant: some older Greek manuscripts omit the pronoun 'his' before 'father and mother' in verse 31, making it a more general statement about leaving parents. JFB mentions that the oldest manuscripts omit 'his.' The variant does not change the meaning. The verse is a quotation of Genesis 2:24, which exists in both Hebrew and Greek forms with minor differences; Paul generally follows the Septuagint. No significant variants alter the sense of the passage.

From the early centuries, this verse has been a foundational text for Christian teaching on marriage. The early church saw in the 'one flesh' union a reflection of Christ’s union with the church, often reading it through a typological lens. In the medieval period, it was cited in marriage liturgies and discussions of the sacramentality of marriage. The Reformation continued this emphasis, with both Catholic and Protestant theologians grounding their marriage theologies in this passage. In modern biblical scholarship, Ephesians 5:31 remains central to discussions of the household codes, the theology of marriage, and the ecclesiology of the church as the bride of Christ. It is frequently quoted in wedding ceremonies across Christian traditions.

Three-point outline

1. Leaving, The marriage bond reorders primary loyalties. Paul quotes Genesis to show that a man leaves father and mother to form a new family unit. This is not abandonment but a redefinition of priority. The shift from parents to spouse reflects the creation pattern in which the two become one.
2. Cleaving, The verb “joined” (προσκολληθήσεται) carries the force of being glued or cemented. It implies permanence and intimacy. God is the active agent in this joining. The passive voice points to divine action, the couple does not merely decide to stay together; God binds them as one.
3. Becoming one flesh, The phrase “shall become one flesh” (εἰς σάρκα μίαν) points to a new unity that includes physical, emotional, and spiritual dimensions. It is a becoming, not a static state. This union mirrors Christ’s union with the church, where believers are members of His body (Eph 5:30).

Five-point outline

1. The origin of the quote, Paul draws from Genesis 2:24, the inspired commentary on the first marriage. This roots Christian marriage in creation, not culture.
2. The action of leaving, Marriage signals a new household. The man (and by implication the woman) reorders family ties. This was countercultural in a society where extended family control often persisted.
3. The action of joining, God does the joining. The passive verb suggests that marriage is not merely a human contract but a divine covenant.
4. The result of one flesh, The two become a new entity. This includes sexual union but goes beyond it to a whole-life partnership.
5. The mystery of Christ and the church, Paul’s primary application is not marriage advice but gospel revelation. Marriage is a signpost pointing to the permanent, self-giving union between Christ and His bride, the church.

Illustration hooks

• Wood glue, Good wood glue, when set, holds so well that the wood breaks before the glue joint. The word “joined” (προσκολληθήσεται) carries that same idea, a bond stronger than the parts it connects. (This illustration is adapted from Adam Clarke’s commentary.)
• Two rivers merging, When two rivers converge, they do not simply flow side by side; they become one stream with a new name and character. The “becoming one flesh” is not a blending of identities but a creation of a new shared identity.

Questions your congregation is asking

• If marriage is supposed to reflect Christ and the church, what does that look like when a marriage is hard or broken?
• Does this passage mean that a person must always put their spouse above their parents? How does that work practically?
• If Paul is really talking about Christ and the church, does that mean the primary meaning of Genesis 2:24 is about the gospel, not about marriage?

This verse sits at the hinge of Paul’s teaching on marriage. He has just told husbands to love their wives as Christ loved the church, and he grounds that command in the creation account. As you discuss this passage, pay attention to how Paul draws a straight line from the first marriage to the union of Christ and believers. What does it mean for a marriage to be a living picture of the gospel?

Discussion questions

1. Read Genesis 2:24 and Ephesians 5:31 side by side. What differences do you notice in how Paul quotes the Old Testament? Why might he change the wording (e.g., “the two will become one flesh” vs. “they shall be one flesh”)?
2. The Greek verb for “joined” (προσκολληθήσεται) is passive, “will be joined.” Who is the one doing the joining? How does that affect how we think about marriage as a covenant?
3. Verse 32 says, “This mystery is great, but I speak concerning Christ and the assembly.” Does that mean Paul thinks marriage is really about Jesus, or is he simply using marriage as an illustration? What evidence in the text supports your view?
4. How does the “one flesh” union differ from a simple partnership or cohabitation? What does it mean to become one flesh emotionally, practically, and spiritually?
5. Why does Paul include the detail about leaving father and mother? In what ways is marriage a reordering of priorities, and is that always easy to carry out?
6. If a marriage is supposed to reflect Christ and the church, what does a healthy marriage look like when the husband and wife both have flaws?
7. How does this passage shape the way you view your own marriage (or a marriage you care about) as more than a private relationship?