“What does it mean to be one flesh in a marriage?”……The term “one flesh” comes from the Genesis account of the creation of Eve. It describes the process by which God created Eve from a rib taken from Adam’s side as he slept.

Genesis 2:21-24 So the Lord God caused the man to fall into a deep sleep. While the man slept, the Lord God took out one of the man’s ribs[a] and closed up the opening. 22 Then the Lord God made a woman from the rib, and he brought her to the man. “At last!” the man exclaimed.“This one is bone from my bone, and flesh from my flesh!She will be called ‘woman,’ because she was taken from ‘man.’” This explains why a man leaves his father and mother and is joined to his wife, and the two are united into one.

Adam recognized that Eve was part of him—they were in fact “one flesh.”

The term “one flesh” means that just as our bodies are one whole entity and cannot be divided into pieces and still be a whole, so God intended it to be with the marriage relationship. There are no longer two entities (two individuals), but now there is one entity (a married couple). There are a number of aspects to this new union.……As far as emotional attachments are concerned, the new unit takes precedence over all previous and future relationships

Genesis 2:24This explains why a man leaves his father and mother and is joined to his wife, and the two are united into one..

Some marriage partners continue to place greater weight upon ties with parents than with the new partner. This is a recipe for disaster in the marriage and is a perversion of God’s original intention of “leaving and cleaving.” A similar problem can develop when a spouse begins to draw closer to a child to meet emotional needs rather than to his or her partner.……Emotionally, spiritually, intellectually, financially, and in every other way, the couple is to become one. Even as one part of the body cares for the other body parts (the stomach digests food for the body, the brain directs the body for the good of the whole, the hands work for the sake of the body, etc.), so each partner in the marriage is to care for the other.

Each partner is no longer to see money earned as “my” money; but rather as “our” money.

Ephesians 5:22-33 …For wives, this means submit to your husbands as to the Lord. 23 For a husband is the head of his wife as Christ is the head of the church. He is the Savior of his body, the church.  As the church submits to Christ, so you wives should submit to your husbands in everything. For husbands, this means love your wives, just as Christ loved the church. He gave up his life for her to make her holy and clean, washed by the cleansing of God’s word. (Greek washed by water with the word.) He did this to present her to himself as a glorious church without a spot or wrinkle or any other blemish. Instead, she will be holy and without fault.  In the same way, husbands ought to love their wives as they love their own bodies. For a man who loves his wife actually shows love for himself. 29 No one hates his own body but feeds and cares for it, just as Christ cares for the church. 30 And we are members of his body.

As the Scriptures say, “A man leaves his father and mother and is joined to his wife, and the two are united into one.” This is a great mystery, but it is an illustration of the way Christ and the church are one. So again I say, each man must love his wife as he loves himself, and the wife must respect her husband

Proverbs 31:10-31 give the application of this “oneness” to the role of the husband and to the wife, respectively.

A Wife of Noble Character

Who can find a virtuous and capable wife? …She is more precious than rubies.Her husband can trust her, and she will greatly enrich his life. …She brings him good, not harm, all the days of her life. …She finds wool and flax and busily spins it.…She is like a merchant’s ship, bringing her food from afar.…She gets up before dawn to prepare breakfast for her household and plan the day’s work for her servant girls.

She goes to inspect a field and buys it; with her earnings she plants a vineyard.…She is energetic and strong, a hard worker.…She makes sure her dealings are profitable; her lamp burns late into the night. Her hands are busy spinning thread, her fingers twisting fiber.…She extends a helping hand to the poor and opens her arms to the needy.…She has no fear of winter for her household, for everyone has warm clothes.…She makes her own bedspreads.…She dresses in fine linen and purple gowns. Her husband is well known at the city gates, where he sits with the other civic leaders.…She makes belted linen garments and sashes to sell to the merchants.…She is clothed with strength and dignity, and she laughs without fear of the future.…When she speaks, her words are wise, and she gives instructions with kindness.…She carefully watches everything in her household and suffers nothing from laziness.…Her children stand and bless her. Her husband praises her:…“There are many virtuous and capable women in the world, but you surpass them all!”…Charm is deceptive, and beauty does not last; but a woman who fears the Lord will be greatly praised. Reward her for all she has done. Let her deeds publicly declare her praise.

Physically, they become one flesh, and the result of that one flesh is found in the children that their union produces; these children now possess a special genetic makeup, specific to their union. Even in the sexual aspect of their relationship, a husband and wife are not to consider their bodies as their own but as belonging to their partner

1 Corinthians 7:3-5. The husband should fulfill his wife’s sexual needs, and the wife should fulfill her husband’s needs.The wife gives authority over her body to her husband, and the husband gives authority over his body to his wife. Do not deprive each other of sexual relations, unless you both agree to refrain from sexual intimacy for a limited time so you can give yourselves more completely to prayer. Afterward, you should come together again so that Satan won’t be able to tempt you because of your lack of self-control.

Nor are they to focus on their own pleasure but rather the giving of pleasure to their spouse.……This oneness and desire to benefit each other is not automatic, especially after mankind’s fall into sin.

The man, in Genesis 2:24 (KJV), is told to “cleave” to his wife. This word has two ideas behind it.

One is to be “glued” to his wife, a picture of how tight the marriage bond is to be.

The other aspect is to “pursue hard after” the wife. This “pursuing hard after” is to go beyond the courtship leading to marriage, and is to continue throughout the marriage.

The fleshly tendency is to “do what feels good to me” rather than to consider what will benefit the spouse. And this self-centeredness is the rut that marriages commonly fall into once the “honeymoon is over.” Instead of each spouse dwelling upon how his or her own needs are not being met, he or she is to remain focused on meeting the needs of the spouse.……As nice as it may be for two people to live together meeting each other’s needs, God has a higher calling for the marriage. Even as they were to be serving Christ with their lives before marriage

Romans 12:1-2And so, dear brothers and sisters, I plead with you to give your bodies to God because of all he has done for you. Let them be a living and holy sacrifice—the kind he will find acceptable. This is truly the way to worship him.Don’t copy the behavior and customs of this world, but let God transform you into a new person by changing the way you think. Then you will learn to know God’s will for you, which is good and pleasing and perfect.

They are now to serve Christ together as a unit and raise their children to serve God

1 Corinthians 7:29-34The time that remains is very short. So from now on, those with wives should not focus only on their marriage.Those who weep or who rejoice or who buy things should not be absorbed by their weeping or their joy or their possessions.Those who use the things of the world should not become attached to them. For this world as we know it will soon pass away.I want you to be free from the concerns of this life. An unmarried man can spend his time doing the Lord’s work and thinking how to please him.But a married man has to think about his earthly responsibilities and how to please his wife.His interests are divided. In the same way, a woman who is no longer married or has never been married can be devoted to the Lord and holy in body and in spirit. But a married woman has to think about her earthly responsibilities and how to please her husband.

Malachi 2:15Didn’t the Lord make you one with your wife? In body and spirit you are his. And what does he want? Godly children from your union. So guard your heart; remain loyal to the wife of your youth.

Ephesians 6:4Fathers, do not provoke your children to anger by the way you treat them. Rather, bring them up with the discipline and instruction that comes from the Lord.

Priscilla and Aquila, in Acts 18, would be good examples of this. As a couple pursues serving Christ together, the joy which the Spirit gives will fill their marriage

Galatians 5:22-23But the Holy Spirit produces this kind of fruit in our lives: love, joy, peace, patience, kindness, goodness, faithfulness,23 gentleness, and self-control. There is no law against these things!

In the Garden of Eden, there were three present (Adam, Eve, and God), and there was joy.

So, if God is central in a marriage today, there also will be joy.

Without God, a true and full oneness is not possible.