The Mystery and Wonder of “One Flesh”

“Therefore a man shall leave his father and his mother and hold fast to his wife,
and they shall become one flesh.” (Genesis 2:24, ESV)

Perhaps you have wondered what “one flesh” means in Genesis 2:24. I have tried to answer that question many times as a pastor. Certainly “one flesh” sounds intimate. How do two people, a man and woman, become one flesh in a marriage covenant? The context of Genesis 2 suggests that “one flesh” refers to something physical, but is there also something deeper?

The one-flesh bond involves a physical act with the potential of reproducing another human being.

The context in Genesis focuses upon Adam’s need for a partner if he/they were to populate the earth. Our physical bodies reflect our uniqueness as male and female to complement each other in the act of reproduction. And that is something that a relationship between two men or two women can never accomplish—no matter what people may claim today.


God had created the animals out of the soil and commanded them to multiply and fill the earth. He also formed the man from the dust of the ground and placed him in the garden to manage it. Adam was to name the animals. (I like to imagine each pair of animals—male and female—passing before Adam to receive their name. If sufficient time had passed to permit some of the animals to have already mated, Adam might have seen his first litter of kittens.)

One fact became all too clear: Adam was the only living creature in the garden without a mate. He was alone! Although surrounded by natural beauty and a plethora of amazing animals, Adam must have felt an empty place in his soul. Certainly, he enjoyed the evening visits with his Creator, but something was missing in his life. Someone! Someone to provide the opportunity to reproduce another human being and to populate the earth.
Someone like himself but…delightfully different as well.

It is at this point in Genesis that we discover the first negative words recorded in Scripture—words from the lips of the Creator Himself:
“It is not good that the man should be alone; I will make him a helper fit for him.” (Genesis 2:18)
So the LORD God caused a deep sleep to fall upon the man, and while he slept took one of his ribs and closed up its place with flesh. And the rib that the LORD God had taken from the man he made into a woman and brought her to the man.
Then the man said,
“This at last is bone of my bones
and flesh of my flesh;
she shall be called Woman,
because she was taken out of Man.”
(Genesis 2:21–23, ESV)

Adam’s almost spontaneous response, upon discovering the partner that God had created from him and for him, is the first poetry recorded in the Bible.

Because the woman was formed out of the man (Ish), Adam named her Ishah. Note the play on words. This new arrival in the garden was unique from all the animals that Adam had named. She was “like him” because she shared his flesh and bones. Simply speaking, our physical bodies primarily consist of flesh and bones. Our skeletons serve as a frame on which to attach muscles and a shell to encase and protect our vital organs.
The poetry ends at this point.

Verse 24 introduces commentary to describe this unique covenant relationship between one man and one woman.

“Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. And the man and his wife were both naked and were not ashamed.” (Genesis 2:24–25, ESV)

The man was to leave his family and to commit himself to his wife. The Hebrew word translated “hold fast to” or “cling to” could be translated “fuse himself to” his wife. (“Fuse” is the word that I used in a previous post, borrowed from a scientific article describing how the fusion of an egg and a sperm forms one cell called a Zygote, a new living organism capable of reproducing itself and becoming another human being.) That wonderful mystery of two cells fusing together to become one cell helps illustrate the biblical description of marriage as two people.

A man and a woman becoming “one flesh.”

Note the comment that follows the words “one flesh”: “And the man and his wife were both naked and were not ashamed.” Clearly, there is a physical/sexual aspect in the one-flesh relationship within the marriage covenant between a husband and wife, with the Creator-God as both a witness and partner. This, of course, is a covenant far, far deeper than today’s “hooking up” or “recreational sex.”

Could there be clearer evidence of God’s plan for marriage? “One flesh”—no longer two—with the wonderful, almost mystical ability to reproduce another human being! And this carries with it the clear and natural assumption that the baby will be protected while it matures inside its mother’s womb for nine months, preparing for its first gasp of oxygen with its own lungs and its first cry with its own vocal cords!

One flesh involves something deeper than physical.

Stepping outside Genesis 2, consider evidence from the New Testament that “one-flesh” relationship includes something deeper than a physical act. Something almost spiritual. (I hesitate to use the word “spiritual” because of its overuse today. Anything and almost everything has been described as being a spiritual experience. Sharing a white chocolate latte by candlelight with a friend is considered “spiritual.” Even a walk along the beach or gazing up at the stars on a clear night.)

Consider Paul’s warning against sex outside of the marriage covenant—a behavior almost considered “normal” in the Corinthian culture:
“The body is not meant for sexual immorality, but for the Lord, and the Lord for the body. By his power God raised the Lord from the dead, and he will raise us also. Do you not know that your bodies are members of Christ himself? Shall I take the members of Christ and unite them with a prostitute? Never! Do you not know that he who unites himself with a prostitute is one with her in body? For it is said, ‘The two shall become one flesh.’ But he who unites himself with the Lord is one with him in spirit.” (1 Corinthians 6:13-16)

Clearly, in the above passage, “one flesh” involves something deeper than a flesh-on-flesh physical act. When the man in Paul’s illustration “united himself” with a prostitute, the two became “one flesh.” That one-night stand was a cheap reflection of the almost sacred act within a marriage covenant. (However, two men or two women in a homosexual relationship can never become “one flesh.” They will always remain two. Such sexual activity is not simply immoral; it is unnatural—an attack against nature itself. God considers it an abomination.)

Because God is both witness and co-participant in the sacred marriage covenant, to violate the one-flesh covenant is to sin against Christ, against the Holy Spirit who dwells within a believer and against our own bodies. Sounds like spiritual suicide.
Paul continues his instructions regarding sex and marriage in 1 Corinthians 7, where “one flesh” has deep, spiritual connotations. Sex is both a privilege to enjoy and a responsibility. Sex can strengthen the marital bond when each partner seeks to serve the other. Paul also warns that Satan will attempt to use sex as a weapon to weaken the marital covenant, so it seems there is something spiritual about becoming one flesh.

One flesh includes the potential to experience a deeper social relationship.

Consider Paul’s instructions to the church at Ephesus:
“Husbands, love your wives, as Christ loved the church and gave himself up for her, that he might sanctify her, having cleansed her by the washing of water with the word, so that he might present the church to himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish. In the same way husbands should love their wives as their own bodies. He who loves his wife loves himself. For no one ever hated his own flesh, but nourishes and cherishes it, just as Christ does the church, because we are members of his body. “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” This mystery is profound, and I am saying that it refers to Christ and the church. However, let each one of you love his wife as himself, and let the wife see that she respects her husband.” (Ephesians 5:25–33, ESV)

Something amazingly profound happens in the covenant relationship. So amazing that Paul actually calls it a mystery. Christ’s unselfish love for His bride—the Church—is the model for a Christian husband. Christ literally gave Himself up for the Church. It cost His life. He is committed to making us holy like Himself. He loves the Church as if it was His own body, and we are. In the same way, a godly husband will cherish and protect his wife as he would his own life. It is in this unselfish relationship that personal relationships can grow deeply.

Paul, once again, reaches back to Genesis 2. Just Imagine two people entering into a covenant that fuses them into one flesh, with each unselfishly cherishing the other. Such selfless commitment will draw them closer and grow them deeper into their relationship. Imagine the potential for true intimacy. It’s wonderful! I know, for I speak as a man that has been married to the same woman over 57 years. The love, the trust and the desire to please each other has grown deeper until we almost think as one. This is the relational aspect of becoming “one flesh.”

So, once again, Paul has anchored his teaching about marriage on the one-flesh statement in Genesis.

The one-flesh bond is so strong—so severe—that it is to be unbreakable.

When Jesus responded to the Pharisees’ “trick” question about His position on divorce, He refused to land on either the strict or the more permissive views about divorce being taught by various Rabbis. Instead, He reaches back to Genesis 2. “Have you not read that he who created them from the beginning made them male and female, and said, ‘Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh.’ So, they are no longer two but one flesh. What therefore God has joined together, let no man separate.” (Matthew 19:4-6)

Notice that Jesus added this comment to the passage in Genesis: “What therefore God has joined together, let no man separate.”

These are severe words. Words I have used when performing weddings. Regretfully, sometimes the words proved to be no more than ink on paper.

Something has happened, or was intended to happen, when a man and a woman and God entered into a covenant that makes marriage more than a legal contract. More than a sheet of paper to be signed and filed at the county courthouse. So special, so spiritual and so binding is this one-flesh relationship—this covenant before God—that it is almost beyond comprehension. Perhaps it needs to be experienced before one can even begin to comprehend the mystery of two people becoming one flesh.

To willfully, selfishly break this covenant not only derails the personal relationship between the couple but dishonors our Creator. I share a quote from the Expositors Bible Commentary:
“Divorce is contrary to the divine institution, and contrary to the nature of marriage, contrary to the divine action by which the union is affected. It is precisely here that its wickedness becomes singularly apparent—it is the sundering by man of a union God has constituted. Divorce is the breaking of a seal which has been engraven by the hand of God” (Murray, Divorce, p. 33).

So how can two unique people become one flesh? The one-flesh bond involves a physical/sexual relationship intended for pleasure and procreation. One flesh involves such a deepening unselfish love that the partners would literally die for one another. One flesh is a spiritual relationship that reflects Christ’s love for His church. One flesh is a covenant made between two people and God that is so strong it ought only be broken by death.

Next to the privilege of knowing and enjoying God Himself may be to experience the mystery of two people becoming one flesh.