Scripture Reading

Exodus 20:14 You shall not commit adultery.

Matthew 5:27–30 You have heard that it was said to those of old, “You shall not commit adultery.” But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart. If your right eye causes you to sin, pluck it out and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell. And if your right hand causes you to sin, cut it off and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell.

Opening Prayer

O Gracious God and Heavenly Father, we do rejoice and give thanks for Your Word. We know it is our only infallible rule for faith and life, and as we come to these passages, as this commandment before us this morning, we pray that You would open our hearts and our minds to the understanding of Your Word by Your Spirit, and that as Your Word goes forth in the power of the Spirit, we pray that it would find within each of our hearts that rich, fertile soil that brings about great and abundant fruit for Your glory. We pray, Father, for your blessing upon your word. In the name of the Lord Jesus Christ, we pray. Amen.

Introduction to the Seventh Commandment

Well, this morning we come to the seventh commandment in our study of the Ten Commandments.

Some, when they read this particular commandment, might say, “Oh, I never cheated on my spouse or my boyfriend or girlfriend or significant other, so I get a pass on this one.”

But we know that not only does the seventh commandment condemn a variety of actions and behavior, even beyond sexual sins, but it also reaches deep into the heart and exposes sins of thoughts and desires, even as we’ve seen with previous commandments.

When we summarize the seventh commandment by stating that it calls us to pursue purity, it is not just pursuing purity in our marriages or in our bodies, but we are also to pursue and keep pure our hearts, our inner selves, our thoughts and words, as well as our actions.

Indeed, as we seek to conform our lives to holiness and transform how we live, we can’t merely focus on the outward actions and behaviors. We must deal with the heart, bring about a true heart transformation by the grace of God.

The Failure of the Purity Movement

This was really the great failure in many respects of the so-called purity movement that was popular, perhaps it still is, among Christians maybe 20 or so years ago.

The emphasis was only on outward conformity and seeking to preserve or keep pure one’s body. It was all about “don’t touch, don’t look, don’t do this, don’t do that.” But there was little to no effort at seeking the transformation of the heart, which of course is the root of our thoughts, emotions, desires, will, and ultimately our words, and yes, our actions.

This then led to a disconnect between thoughts and actions. Though actions were kept in check, thoughts were running amok. Eventually that which was in the heart became too much to be contained and began to overwhelm the actions.

What you had was a bunch of young people not only falling into sexual sin, but even being so burdened with guilt and shame that they didn’t know how to properly repent and seek forgiveness and healing. Instead they continued on a path leading to sin and destruction, some even making a wreckage of their faith because they were crushed under the weight of the pressure to be pure in body but neglecting the purity of the heart which Christ chiefly desires.

This is why Jesus expounds on the seventh commandment in Matthew 5, not only pointing out the connection to the sins of the heart, but also using very dramatic language to demonstrate the destructive nature of the sins which the seventh commandment forbids.

God’s Design for Marriage and Sexuality

Before we get to what’s condemned and required in this commandment, we first want to consider God’s purpose and design for marriage and for human sexuality. For this, we must go to the beginning.

• God created man from the dust of the earth.
• He created woman from one of the ribs of the man.

When Eve was created, Adam said:

This is now bone of my bones and flesh of my flesh; she shall be called woman because she was taken out of man.

Then the summary statement from the Lord:

Therefore a man shall leave his father and mother and be joined to his wife and they shall become one flesh.

Here we find the creation of the institution of marriage—the one flesh union between one man and one woman.

This institution becomes a foundational building block for the rest of society, including family, government, and even the church. Because from this first union came all of humanity.

It is because of this that the institution of marriage becomes a prime target for Satan’s assaults. Since the fall into sin, human history has revealed this very thing. Whenever God’s purpose and design for marriage is distorted or done away with, a negative effect ripples throughout the rest of society.

Preserving the institution of marriage as God first designed it is critical to every society and every age, including our own.

Sexuality Is a Good Gift

It’s not just about preserving the purity of the marriage bed (as important as that is). It’s also about pursuing purity in God’s design and purpose for intimacy.

Human sexuality isn’t an evil to be shunned and suppressed. It is a good gift God gives to a husband and wife united together in marriage.

We see this in the creation account:

• When Adam was first created, there was not found a helper comparable to him.
• God said, It is not good that man should be alone.
• God created Eve for this very purpose.

Therefore man shall leave his father and mother and be joined to his wife, and they shall become one flesh.

Intimacy was divinely created between a man and a woman before the fall. It wasn’t evil.

Genesis 2:25 – And they were both naked, the man and his wife, and were not ashamed.

The whole creation account concludes:

God saw everything that he had made and indeed it was very good.

All that God had made—this institution of marriage, including the intimacy between a husband and wife—is declared very good.

But according to God’s design, that good gift is placed within the boundaries of the institution of marriage between one man and one woman.

Yet after the fall, this was one of the first things that came under attack and which now in our own day continues in a variety of perverse ways.

The seventh commandment calls us to pursue the purity of God’s design for marriage and for human sexuality.

Practical Application: Building a Strong Marriage

How is this done practically?

It is chiefly accomplished by building a strong, healthy marriage that respects the boundaries God has put into place. This includes protecting the marriage relationship against the sin of adultery.

Jesus begins in Matthew 5:

You have heard that it was said to those of old, you shall not commit adultery.

Strictly speaking, adultery is when one violates the one-flesh union of marriage by having relations with someone who isn’t their husband or wife. It corrupts this intimate union with the addition of a third party and destroys the unity of marriage at its most basic level.

So significant was this violation that the punishment prescribed in Israel was death (Leviticus 20:10). The New Testament reinforces:

Hebrews 13:4 – Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge.

God does not take lightly the corruption of what He Himself has graciously designed and given as a wonderful gift.

Sins Forbidden in the Seventh Commandment (Westminster Larger Catechism Q139)

The sins forbidden, besides the neglect of the duties required, are:

• adultery
• fornication
• rape
• incest
• sodomy
• all unnatural lusts
• all unclean imaginations, thoughts, purposes and affections
• all corrupt or filthy communications or listening thereunto
• wanton looks
• impudent or light behavior
• immodest apparel
• prohibiting of lawful and dispensing with unlawful marriages
• allowing, tolerating, keeping of stews [brothels], and resorting to them
• entangling vows of single life
• undue delay of marriage
• having more wives or husbands than one at the same time
• unjust divorce or desertion
• idleness, gluttony, drunkenness, unchaste company
• lascivious songs, books, pictures, dancing, stage plays
• all other provocations to, or acts of uncleanness, either in ourselves or others.

As you read through this list, it doesn’t take long to realize that every one of these is displayed, promoted, and even celebrated in our society and culture today.

Notable Examples in Our Day

• Polygamy – corruption seen early (Lamech) and among patriarchs; always brought trouble.
• Unbiblical divorce and remarriage – compounds sin upon sin.
• Fornication / sexual immorality – premarital sex, prostitution, incest, rape, pornography, etc.Ephesians 5:3 – But fornication and all uncleanness… let it not even be named among you, as is fitting for saints.
• Sodomy and unnatural lusts – homosexual behavior and desires.Romans 1 – Women exchanged the natural use… men… burning in their lust for one another.

Anything outside the one-flesh union of one man and one woman in the covenant of marriage is a violation of God’s design and is therefore sinful. Sexuality outside this boundary leaves deep scars and wounds that aren’t easily healed.

The Heart Is the Root

We too often only focus on deeds and consider these the key sins of the seventh commandment.

But deeds begin in the heart—with thoughts and desires. They progress as a downward spiral that, if unchecked, will eventually lead to deeds.

We see this in Genesis 3 (the fall) and explicitly in Jesus’ teaching:

Matthew 5:28 – But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart.

Jesus makes clear: it’s not just the act, but the lustful thoughts and desires that flow from the heart.

Matthew 15:19 – For out of the heart proceed evil thoughts, murders, adulteries, fornications…

From God’s sight, sinful thoughts and desires of the heart are just as worthy of His wrath as the actions they lead to.

Jesus is not saying it is sinful simply to look at a woman. He is saying if a man looks with lustful intent—to seduce, fantasize, or covet—then he is guilty.

This applies to all men (married or not) and, though not restated in feminine language, easily to women as well.

1 Corinthians 6:18 – Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body.

Sexual immorality damages:

• your own body
• the union with your spouse (present or future)
• the Lord (your body is the temple of the Holy Spirit)

Radical Measures Required

Jesus uses alarming, graphic language on purpose:

Matthew 5:29–30 – If your right eye causes you to sin, pluck it out… If your right hand causes you to sin, cut it off… For it is more profitable for you that one of your members perish, than for your whole body to be cast into hell.

Jesus is speaking figuratively to drive home the severity of this sin. He is not advocating self-mutilation.

The point: Cut out the sin—radically and quickly.

Practical examples:

• Turn your eyes away when lust begins.
• Walk out of sexually explicit movies.
• Change the station from explicit songs.
• Stay away from pornography in all forms.
• Don’t put yourself alone with someone who is not your spouse.
• Keep boundaries on social media.
• Avoid friends who tempt or encourage sin.

Flee like Joseph fled from Potiphar’s wife.

Sexual sin destroys individuals, marriages, families, churches, and nations. Take radical measures.

Hope and Forgiveness in Christ

If you do sin—if you fall into sexual immorality, lust, pornography, or any form—there is hope.

1 Corinthians 6:9–11 Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites… will inherit the kingdom of God. And such were some of you. But you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus and by the Spirit of our God.

You can secure this hope by:

• repenting
• confessing sin to God
• believing the gospel

1 John 1:9 – If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.

Daily rest upon the grace of God to flee temptation.

If married, pray diligently to be true to your vows and strengthen your marriage to reflect Christ and the church.

Your pursuit of purity—single or married—will be a witness to a world crushed under sexual sin, that they too might see Jesus and be washed, sanctified, and justified.

Praise to the Lord God, all glory to Him. Amen.

Closing Prayer

O gracious God and Heavenly Father, we do rejoice and give thanks for this important word and this commandment that you have given, this challenge to pursue purity, but not just in an outward manner, but that we would pursue purity, not just in our actions, but in our thoughts and our minds and our hearts that we might truly enjoy the blessings and the benefits that you have bestowed upon us, that you have given and provided in that institution of marriage between one man and one woman.

We look around and we see all sorts of corruptions of this institution in so-called marriages that are a mockery of your design, and how our nation has wickedly embraced these things.

We pray, Father, that as we strive in Your grace to live pure and holy lives, to flee from sexual immorality, we know we’re going to stand out from the rest of the world that will be mocked and laughed at.

But we pray that there would be those that we would be a witness to, that they would see the beauty of what you have designed, that they would see the glory of the one man, one woman union in marriage, and that they would see in us and in our marriages and our families and our relationships, that they would especially see Jesus, our precious Lord and Savior, who gave his life for us.

Because we once were this way, enslaved to sin. But now in Christ, we are no longer.

We pray that you would enable us by your grace to walk daily in the light of that grace, striving after holiness and purity, all to the praise of your glorious name.

Father, we pray that you would impress these truths upon each of our hearts, drawing us all closer to yourself, that we would be these faithful witnesses here and throughout all the earth.

In the name of the Lord Jesus Christ, we pray. Amen.