Sex, Marriage, and Becoming One Flesh

HomeChristianity and the BibleSex, Marriage, and Becoming One Flesh

How does the Bible define marriage? What is marriage in God’s eyes? Is it okay for people to have sex before they’re married? These questions are not only important, but they’re increasingly relevant as people, young and old, revisit their ideas about relationships.

Some want to complain that the Bible is strict about issues of sex and sexuality. Well, they’re right. The Bible does prescribe narrow boundaries for sex and marriage, and for some very good reasons. The primary reason? Because marriage isn’t about you, or me, or any other human being. Marriage is about God… and, for that reason, it carries a lot of weight.

God as Husband

You see, throughout the Bible marriage is used as a picture of our relationship with God. In the Old Testament, God is depicted as the husband of the ancient Israelites. Here are a few examples:

One can’t read Hosea without recognizing this imagery. God told Hosea, a righteous man, to marry Gomer, an unrighteous woman. She had been promiscuous, and would be unfaithful to Hosea. This was a symbol… a message to the Israelites about their own unfaithfulness to God. He called them “an adulterous wife.” The ancient Israelites had engaged in idolatry, worshipping other gods and combining the worship of Yahweh with the worship of others. God used the imagery of marriage to describe their relationship with Him. He was the faithful husband, she the adulterous wife.

Jesus as Bridegroom

In the New Testament, Jesus is called the Bridegroom and the church – that is, those who trust in Him – are called the Bride. Here are a few examples:

At the beginning of Jesus’ ministry, John the Baptist described Him as a bridegroom. At the end of time, as described in Revelation, the Bridegroom and the Bride – we who are born again – will finally be united. Throughout Scripture, we see God using marriage to represent our relationship to Him: beloved, and wanted.

No, we won’t actually be married to God… not in the sense that one human marries another. It’s a metaphor. It’s a word picture, kind of like a parable: it uses a familiar, temporary, earthly thing to teach us something about an unfamiliar, eternal, heavenly thing. Consider some of what makes marriage so special, and consider how they reflect the way the Bible describes our relationship with God:

Not all marriages are like that, of course. When they are not, we recognize that things are not as they should be… and, as a result, we seek more. Ultimately, all suffering points to God, who will ultimately remove all suffering.

No marriage in Heaven

I’ve been happily married since 1989. I had read Luke 20 before my wedding, but it was only after I got married that I paid close attention to it. Jesus was asked about marriage in Heaven, and this is His response:

The people of this age marry and are given in marriage. But those who are considered worthy of taking part in the age to come and in the resurrection from the dead will neither marry nor be given in marriage.

As a new husband, reading that caused some distress. I didn’t want to lose my relationship with my wife. That sounds tragic! Of course, Jesus didn’t say that. He said that people won’t be married in Heaven. Why would He say that?

Simple: marriage isn’t an end unto itself. Marriage is a means to another end. Marriage has a GOAL.

The purpose of marriage

If marriage has a purpose, what is it? What can we conclude from Scripture, and from how God uses marriage to make a point? It seems clear: marriage points us to God.

You see, God didn’t have to make us the way we are. He made us this way on purpose. He knows what He’s doing. Why do we have to eat? Because God wants us to learn something. We hunger for food, and that hunger goes away when we eat. Of course, that doesn’t last forever. We get hungry again, and again, and again. We can only partially satisfy our hunger.

In John 6, Jesus called Himself “the bread of life.” He told the crowd that those who come to Him would never be hungry again. Obviously, Christians still need to eat. He was using a metaphor: our spiritual hunger is satisfied when we finally find the true food we were created to eat.

The same is true of every other desire we have. God created us with each and every desire we have. He did this purposefully, to help us see our need for Him. We get lonely, so we want companions. We seek someone to love, who will love us in return. We want to be known, to be understood.

A good marriage looks a lot like God’s love for us… and that’s the point. Marriage teaches us about God. A good marriage shows us what He is like, and points to our desires finally being utterly fulfilled. A bad marriage – a tragedy – does help us see that this world is broken, that no other person can meet all of our deepest needs, and makes us hungry to the One who can.

It all starts in Genesis.

One Flesh

In Genesis 2:24 we read this:

… a man leaves his father and mother and is united to his wife, and they become one flesh.

In Matthew 19:4-6 we read this:

… at the beginning of creation God ‘made them male and female.’ For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh. So they are no longer two, but one flesh. Therefore what God has joined together, let no one separate.

Finally, here’s 1 Corinthians 6:15-16:

Do you not know that your bodies are members of Christ himself? Shall I then 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 will become one flesh.”

Having sex makes you one flesh. You’re no longer two, but one. This is really, really important. Whether we have sex with a spouse or with a prostitute, we become united with them. This is a spiritual thing: as Jesus pointed out in Matthew, we are joined in this way by God Himself.


Marriage has traditionally been called a “covenant.” A covenant is like a promise, but more. It’s really a set of promises that are intended to be permanent. These days, covenants are a pretty foreign idea. In Jesus’ time, they were fairly common and very well known.

If two people wanted to form a kind of permanent partnership, they would make a covenant with each other. The covenant was intended to include the two, and their households, and their descendants. While there may have been different arrangements, a typical covenant would include promises of provision, protection, and identity. The two would promise to provide for each other in difficult times, symbolized by trading wallets. They would promise to protect each other from danger, symbolized by trading cloaks. Finally, when someone thought of one of the two, they would automatically think of the other… symbolized by exchanging names.

We see some of this in the name changes in the Bible. Before God made a covenant with Abraham and Sarah, their names were Abram and Sarai. After the covenant, they added the AH sound to their names. The AH sound comes from Yahweh, the one they were in covenant with. When you encountered Abraham, you would think of Yahweh.

That, by the way, is a good example of how people should see Christians: when they see us, they should think of Jesus, the one who made a new covenant with us.

When we understand the basics of covenants, we can see why marriage has been called a covenant. Our marriage ceremonies have traditionally expressed those promises. Here’s a common set of promises used in many marriages:

As you can see, these kind of promises reflect a typical covenant from Jesus’ day. The tradition of exchanging names is also common, where a wife would change her last name to match her husband’s. When you would think of her, you would also think of him.

Clinging to God

Let’s go back to Genesis 2, where we see that ‘a man leaves his father and mother and is united to his wife, and they become one flesh.’ The word we translate as “united” is the Hebrew DABAQ. It means to cling to, to stay close to, or to be joined to another. The interesting part is that this is the same word used in Deuteronomy 13:1-4.

If a prophet, or one who foretells by dreams, appears among you and announces to you a sign or wonder, and if the sign or wonder spoken of takes place, and the prophet says, “Let us follow other gods” (gods you have not known) “and let us worship them,” you must not listen to the words of that prophet or dreamer. The Lord your God is testing you to find out whether you love him with all your heart and with all your soul. It is the Lord your God you must follow, and him you must revere. Keep his commands and obey him; serve him and hold fast to him.

Being united in marriage, in Genesis 2, is the same word as holding fast to God. Again and again we see that marriage is an earthly expression of a spiritual reality. Just as a husband and wife are to be united, we are to be united with God. In this life, that union takes the form of trusting God with our lives, and never following other gods. In the Old Testament, marital unfaithfulness is equated to spiritual unfaithfulness. The ancient Israelites didn’t only worship Yahweh… too often, they added the worship of other gods as well.

Jesus’ Yoke

Followers of Jesus are to be single-minded in our devotion to Him. We aren’t to unite ourselves with other gods, obviously… but we’re also taught to make sure that when we are united with others, we’re united together by our common commitment to Him. In 2 Corinthians 6:14-16 Paul warned us:

Do not be yoked together with unbelievers. For what do righteousness and wickedness have in common? Or what fellowship can light have with darkness? What harmony is there between Christ and Belial? Or what does a believer have in common with an unbeliever? What agreement is there between the temple of God and idols? For we are the temple of the living God.

A “yoke” is a kind of harness that connects two farm animals, like oxen, together. The idea is that they can be more effective at plowing a field when they’re joined together. If a young ox needs to be trained, they would yoke it to an older ox. It would learn to pull in the same direction as the older ox, and together they would get the work done.

Paul warned believers to not be connected to unbelievers in this way. When two people are closely connected but heading in different directions, there’s always conflict. People who follow Jesus are to have the same goal in mind: to seek first God’s Kingdom. Jesus spoke in Matthew 11:28-30 about yoking ourselves to Him. In this picture, He’s the older and wiser and well-trained ox who will help us head in the right direction, and who will teach us how the work of the kingdom should be done:

Come to me, all you who are weary and burdened, and I will give you rest. Take my yoke upon you and learn from me, for I am gentle and humble in heart, and you will find rest for your souls. For my yoke is easy and my burden is light.

Putting things together

Marriage is supposed to reflect our relationship with God. We can be ‘one flesh’ with someone without being in covenant, but that’s not good. That is, biblically speaking, yoking yourself to someone unwisely. We’re supposed to be in covenant. As Adam “clung” to Eve and made himself one flesh with her, we’re to do the same.

You can be in covenant with someone without being one flesh with them. That happened all the time in ancient Israel. Marriage, on the other hand, is BOTH: it’s becoming one flesh while in covenant with another. We’re to yoke ourselves together in covenant, and become one flesh, under that permanent commitment.

Marriage is a promise of provision, protection, and identity with another person, their household, and their descendants. Becoming one flesh with your covenant partner is a picture of our union with Christ. Not everyone will be married, so there are times when the picture is incomplete… but an incomplete picture is not at all like a distorted picture.

Don’t distort the picture

As human beings with the ability to choose for ourselves how we will live, there are many situations in which we can distort the picture God has given us. If the purpose of marriage is to make that picture clear, then distorting the covenantal one-flesh relationship of marriage makes it harder for people to know and understand God.

That’s bad.

Here are a few examples of the kind of situations we put ourselves in that distort the picture of God as Israel’s husband, and of Jesus as our bridegroom:

All of these things are distortions of the picture God has presented in Scripture. If salvation has any meaning, anything that undermines God’s goal of being understood by humanity must be considered harmful. Things that make it harder to trust God are bad, and things that make it easier are good. When the picture God painted in Scripture is replicated in the lives of people around us, it’s an obvious blessing and an inspiration.

Sexual Immorality

The Bible speaks often of sexual immorality. Here’s what Paul wrote in 1 Corinthians 6-18 about the subject:

Flee from sexual immorality. All other sins a person commits are outside the body, but whoever sins sexually, sins against their own body. Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; you were bought at a price. Therefore honor God with your bodies.

People think the Bible is strict about sex. It is… not arbitrarily, but because it’s important. As followers of Jesus Christ, we’re not free to do whatever we want with our lives. We belong to Him, and we’re to seek first His kingdom. Our job is to represent Him in all we do, and that includes how we handle issues of sex and sexuality.

If we keep in mind the info about covenants and becoming one flesh, here are a few simple definitions as outlined in the Bible:

Both are condemned in Scripture because they distort the picture of who God is in relation to humanity.

Questions and Feedback

What about the marriage ceremony? Isn’t that important?

What I’ve described above is a kind of ‘mechanical’ description of how things work. Technically speaking, a marriage ceremony has nothing directly to do with whether two people are in covenant. Instead, the marriage ceremony is a public declaration of your intention to be in covenant. That is good, and useful, and beneficial.

Who are you to tell people who they can love?

This question is a knee-jerk reaction that doesn’t have anything to do with what’s written above. First, I’m not telling anyone to do, or not do, anything at all. I’m trying to explain the biblical description of marriage, why it’s important, and to encourage people to consider living by what God has said. The choice is theirs. Second, Jesus taught that we should love God, love our neighbors, and love our enemies. That pretty much covers the whole world. What Jesus did not teach is that it’s okay to become one flesh with whomever you wish. He taught that we should seek first God’s kingdom, and that we’re to be yoked together with people who do the same. Part of seeking God’s kingdom is knowing what the King has said.

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One response to “Sex, Marriage, and Becoming One Flesh”

  1. Joel says:

    Simply accurate and true.

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