Guard Your Purity

The following article “Guard Your Purity” is provided with permission by Grace to You Ministries a ministry of Pastor John MacArthur.  This article originally appeared here at Grace to You (


by John MacArthur

You probably hear a lot about how much our society has progressed. Whether it’s technological or scientific advancement, breakthroughs in medicine or manufacturing, or any other area where progress can be measured, we’re eager to see how far we’ve come.

At the same time, the culture is willfully blind to how it’s regressing. Sexual perversion and deviance run rampant, and all kinds of immorality are promoted and paraded as if they are something to be proud of.

Our society looks more and more like the no-shame culture of the ancient Roman world—a world devoted to fulfilling perverse lusts and deviant desires. Believers in the New Testament world faced the same kinds of daily temptations we face—perhaps even worse.

But in the midst of that wicked society, Paul gave believers a clear command to abstain from immorality and live holy lives. In 1 Thessalonians 4:3, he wrote, “For this is the will of God, your sanctification; that is, that you abstain from sexual immorality.”

People often say they’re confused and frustrated with the struggle to find God’s will for their lives. In this passage, Paul spells out God’s will in no uncertain terms. His will is for our sanctification, our spiritual growth. He wants us to be separate from sin—and specifically, sexual immorality.

Those basic instructions would have flown in the face of the common sexual mentality in Thessalonica, just as they contradict the mindset of our modern culture.

Today we’re told that people are basically good, and since they’re basically good and sex is a part of being human, sex is an acceptable way to seek pleasure. We’re also told it’s a fundamental part of our humanity—that it’s a biological need that we shouldn’t deny ourselves. By that skewed definition, casual sex isn’t just a legitimate recreation—it also fulfills our needs.

The same kind of reasoning gave endless license to the no-shame culture of Paul’s day. Prostitutes, concubines, mistresses, homosexuals, transvestites, temple harlots, adulterers, and adulteresses—even pedophilia was permitted in the Roman world. That was the perverse and deviant culture in which Paul commanded believers to “abstain from sexual immorality.”

It’s not a flexible command, either. There’s no room left for interpretation. It’s not a question of “How close can I get without sinning?” You can’t afford to play those kind of games with temptation.

It’s a command for total abstinence from all immorality—not just physical. “But I say to you, that everyone who looks on a woman to lust for her has committed adultery with her already in his heart” (Matthew 5:28). We’ve got to be vigilant to stamp out temptation, even if those temptations are never consummated. The point isn’t to get as close as you can and still avoid it—it’s to stay far enough away that you can be completely separate from it.

And it’s not as if God hates sex—He designed it. Hebrews 13:4, “Let marriage be held in honor among all, and let the marriage bed be undefiled.” There is no defilement or immorality in that relationship in all its God-intended design. But apart from that, abstinence is what God commands. As the writer of Hebrews makes clear at the end of that verse, “Fornicators and adulterers God will judge.”

It’s a difficult command, especially in a culture so given over to pleasure seeking and shameless excess. But it’s a command that comes with built-in encouragement. The Lord wouldn’t order us to abstain from sexual sin if we weren’t able to obey.

A key and often overlooked aspect of God’s goodness is that He doesn’t give us commands we cannot fulfill. He doesn’t taunt us with impossible directions or challenge us with tasks beyond our ability. Part of the assumption in each of God’s commands to us is that, through the assistance of His Spirit, we’re able to accomplish what He has commanded us to do.

So when the Lord commands His people in 1 Thessalonians 4:3 to abstain from sexual immorality, He’s not holding up an unattainable standard. The command to be pure is one we’re able—and expected—to follow.

In fact, the command comes with built-in instruction. In 1 Thessalonians 4:3-5, Paul wrote:

For this is the will of God, your sanctification; that is, that you abstain from sexual immorality; that each of you know how to possess his own vessel in sanctification and honor, not in lustful passion, like the Gentiles who do not know God.

In simple terms, Paul says that sexual purity is a matter of developing self-control.

Whenever I’m speaking to college students or other young people, one of the key lessons I try to drive home is the vital importance of developing life habits that train them to have control of their bodies.

And it’s not just regarding the area of sexual purity—self-control is vital in all parts of your life. People who have trouble eating too much, sleeping too much, talking too much, spending too much money, entertaining themselves too much, or who waste too much time doing nothing are candidates for major moral disasters. You can eliminate many of the most common pitfalls of sin through the basic discipline of self-control.

Paul was well aware of the need for self-control, even in his own life. “I discipline my body and make it my slave, so that, after I have preached to others, I myself will not be disqualified” (1 Corinthians 9:27). Personal discipline helps guard you from all sorts of immorality and hypocrisy.

From a biblical perspective, self-control is about gaining mastery over your body and bringing it under submission to God. “Therefore do not let sin reign in your mortal body so that you obey its lusts, and do not go on presenting the members of your body to sin as instruments of unrighteousness; but present yourselves to God as those alive from the dead, and your members as instruments of righteousness to God” (Romans 6:12). It’s a matter of ignoring the desires of your flesh and disciplining yourself for the purpose of righteousness.

There are two key aspects to gaining that mastery over your body. The first is to feed on the riches of Scripture. Consistent, faithful study of God’s Word stimulates your spiritual growth, sharpens your mind, and strengthens you against temptation. Train yourself to think and live biblically, and you’ll find it increasingly easier to turn away from temptation. “But I say, walk by the Spirit, and you will not carry out the desire of the flesh” (Galatians 5:16).

The second aspect of gaining mastery over your body is starving yourself of opportunities to sin. You know what triggers temptation in you—avoid those people, places, and things at all costs. It does you no good to develop positive patterns if you continue to expose yourself to all kinds of input that corrupts your thinking. You can’t afford to toy with your desires and emotions—you’ve got to flee temptation and never look back.

The capper to Paul’s exhortation for self-control in 1 Thessalonians 4 is his reminder of our new nature in Christ. He’s calling on believers to live godly, self-controlled lives, “not in lustful passion, like the Gentiles who do not know God” (1 Thessalonians 4:5).

Those words echo his challenge to the church at Corinth in 1 Corinthians 6:19-20: “Or do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and that you are not your own? For you have been bought with a price: therefore glorify God in your body.” The Lord didn’t sacrifice His Son and transform us into new creations just so we could wallow in the same kind of immoral filth as the world. We’re no longer bound to sin—we’ve been set free, and we need to live like it.

Biblical purity is impossible without faithful self-discipline. Cultivating self-control is how we’re able to avoid temptation and live the holy lives God commands us to live.

If you’ve spent any time around a toddler, you know that even the simplest, most basic instruction is followed by an unending string of whys. The attitude behind his questions range from inquisitiveness to rebellion, but the inclination to question authority is hardwired into us all.

It’s not enough to be told not to touch the hot stove—we need to know why we shouldn’t touch it. And often, we need firsthand experience of the consequences before we’re willing to do what we’re told. Complete, first-time obedience does not come naturally.

The same is true with the Lord’s commands to believers. We’re not prone to obey immediately, even when He’s clear about the consequences that await our disobedience.

In 1 Thessalonians 4:3-8, Paul spells out the Lord’s command that we abstain from sexual immorality and live pure lives. And he answers the inherent “why” question, telling us what’s in store if we fall short of God’s holy standard.

For this is the will of God, your sanctification; that is, that you abstain from sexual immorality; that each of you know how to possess his own vessel in sanctification and honor, not in lustful passion, like the Gentiles who do not know God; and that no man transgress and defraud his brother in the matter because the Lord is the avenger in all these things, just as we also told you before and solemnly warned you. For God has not called us for the purpose of impurity, but in sanctification. So, he who rejects this is not rejecting man but the God who gives His Holy Spirit to you.

Paul wants us to have a clear understanding of the stakes involved in sexual immorality. It’s not merely a question of individual impurity—there are repercussions for others as well.

We think of defrauding other people in terms of taking advantage of them financially. But the same kind of greedy, selfish thievery happens all the time in relationships. Paul’s instruction is clear—don’t use others for your own gratification.

That’s especially a problem for young people. Young men and women need to be on the lookout for the kinds of predatory people who would take sexual advantage of them. And they need to diligently examine their own hearts to be sure they’re not taking advantage of someone else.

It’s particularly unthinkable that behavior like that would exist within the church, but sadly, it does. Men and women rob each other of their purity and virtue, and they steal from the other person’s future husband or wife.

God’s Word is clear about leading other believers into sin. Matthew 18:6 says, “Whoever causes one of these little ones who believe in Me to stumble, it would be better for him to have a heavy millstone hung around his neck, and to be drowned in the depth of the sea.” We need to cultivate that mindset in ourselves—that the nightmarish horrors of drowning are preferable to causing another believer to sin.

Paul wants us to consider the consequences of sexual sin and to remember the Lord is the one who distributes those consequences. He doesn’t spell out the exact method of God’s vengeance, but the results of sexual sin are destructive and far reaching. It can devastate a marriage, destroy trust and intimacy, or lead to divorce. It can shatter families and all kinds of relationships. It can lead to a variety of temporal troubles, like financial instability or job loss. And it can lead to disease, or even death. There is no end to judgments you heap on yourself when you engage in sexual sin.

In fact, as we saw back in 1 Corinthians 6:9-11, engaging in a continual pattern of sexual sin will bar a person from heaven and consign his eternal soul to torment in hell. Only God’s redemptive grace has delivered us from lives of unbroken impurity. We’ve been washed and sanctified, and sexual sin is unnecessary. It’s intolerable to God and inconsistent with our new nature.

And when it appears, He has every right to act in holy vengeance. Even an occasional sinful act in the life of a believer will bring about the vengeance of God in this life. It invites the Lord’s chastening.

Sexual immorality contradicts the very purpose that God called us to—we weren’t set aside for impurity, but for purity. We need to be growing closer to the Lord in sanctification, and dalliances with immorality only impede and stifle that growth.

What’s more, that sanctifying work is accomplished by the Holy Spirit, and Paul wants us to remember His constant presence when it comes to abstaining from immorality. Purity isn’t a man-made standard—it was established by God according to His design, and is reinforced by His Spirit at work in us.

The immediate, intimate presence of the Lord ought to be a constant reminder and a powerful deterrent against sexual sin—really, against all sin.

In 1 Corinthians 3:16, Paul confronts believers with this important reminder: “Do you not know that you are a temple of God and that the Spirit of God dwells in you?” Sexual sin doesn’t just defile us—it defames the Spirit that lives and works within us.

That’s why we must abstain from sexual immorality.


Copyright 2013, Grace to You. All rights reserved.  Used by permission.

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