This is the third in a series of transitional messages between Romans 8 and 9, and between Bethlehem on one site and Bethlehem on two sites. I am seeking the Lord for priorities that he might want pressed home on our minds as we clarify our identity and goals in these two sites.

Two weeks ago I began with Luke 5 and the authority and power of Christ to help us be effective man-fishers: treasure Christ above all, humble yourself before his unmerited grace, obey his commands (drop the net), and trust his power. When you drop the net, in other words, let’s make personal evangelism a priority in our lives.

Last week we went to Isaiah 58 and pressed home the call for God-exalting good works, especially in the form of social justice and practical deeds of mercy for the poor. I pled that we not be deceived by living in the Disney Land of the world called America, as though there were not hundreds of millions of people starving in the world (more news just this week on Zimbabwe, not to mention North Korea, Sudan, Ethiopia), and millions of babies being killed in the womb, and untold miseries in hospitals and nursing homes and on the streets that Christians can give themselves to in the name of Christ. Pour yourselves out for the poor, Isaiah says, and your light will break forth like the dawn.

Now, today, alongside evangelism and social justice, I want to call us this morning to personal holiness, especially in our sexual lives. If you like mnemonic devices hang these three messages on three S’s: seeking the lost, social justice, and sexual purity. If you didn’t hear those other messages and all you hear now is a sermon on sex and you think: those poor Christians, hung up on sex again. Not quite. We like our sex just fine. What we get bent out of shape about is not sex, but saying that you can’t be passionate about social justice and sexual purity at the same time — precisely because we believe in good society and good sex.

I am aware that there are lots of children in these services. Some of what I say will be plain to you children, and some will not. That’s why we have a happy partnership between the church and your parents. Some things they say become clearer at church, and some things we say become clearer at home. So be sure to ask them about what you don’t understand.

So let’s go first to this text and simply make as clear as we can — even for the children — what the Bible means by sexual purity. Then we will look at why it’s important and then how to fight for it and enjoy it in our lives.

What Does the Bible Mean by “Sexual Purity”?

Verse 3 gets to the point: “For this is the will of God, your sanctification [or your holiness], that is, that you abstain from sexual immorality.” This phrase, “sexual immorality,” (porneia), means mainly fornication — that is, two people acting as if they are married when they are not married. Touching each other and sleeping together in a way God designed only for a man and a woman married to each other. God said this close physical relationship is for married people only. “A man shall leave his father and his mother, and be joined to his wife; and they shall become one flesh” (Genesis 2:24; 1 Corinthians 7:2; Exodus 20:14).

So “sexual immorality” includes sexual relations before marriage and wrong sexual relations among married people. So, children, it means this: Your mom may not go live with another man as her husband. And your dad may not go live with another woman as his wife. That’s the meaning of the seventh commandment: “You shall not commit adultery” (Exodus 20:14). And oh how blessed is the child where mommy and daddy obey!

“When God calls you to himself, he justifies you by faith in Christ.”

Verse 6 also has fornication and adultery in view, because it says “and that no man transgress and defraud his brother in the matter.” This means that another Christian’s wife or daughter is in view and the sin in view is mainly sexual relations with a woman that is not your wife, but belongs to another man. You would sin against her and him.

But let’s not think that the only sexual sin in view here is the behavior of sleeping with a woman not your wife — or a man not your husband. Paul refers in verse 5a to “lustful passion.” “Possess your own vessel in sanctification and honor, not in lustful passion.” The issue here is not just behavior but also sexual desires that dominate your life in ways they should not. For our day I think we could include here desires that lead to the use of pornography, and desires that lead to a fantasy life and masturbation that is so often embedded in it — for men and women.

I have reports on all hands that this issue is huge, and that the easy access to internet pornography and cable TV is capturing many men and women and making slaves out of them. The positive alternative to this is described in verses 1, 3, and 7. Verse 1: “How you ought to walk and please God.” Verse 3: “This is the will of God, your sanctification [or holiness].” Verse 7: “God has not called us for the purpose of impurity, but in sanctification [or holiness].”

When God calls you to himself, he justifies you freely by faith in Christ on the basis of Christ’s blood and righteousness, and he calls you to a life of holiness, which in this context refers explicitly to sexual purity. This is the practical fruit of justification by faith.

That is the what of the text: Bethlehem, what shall we be and do as a church worshipping in two locations? Let us pursue personal holiness, especially sexual purity. Three S’s not just one: seeking the lost, social justice, sexual purity.

Why Should We Be Concerned with Our Sexual Purity?

Now the why. I’m going to deal with this quickly because I really want to move to the “how” — which unpacks the practical effects of the “why.” Why should we be concerned with our sexual purity? The text mentions at least five incentives to fight this battle.

1. The incentive of pleasing God. Verse 1b: Paul exhorts us “how you ought to walk and please God.” Sexual purity pleases God.

2. The incentive of doing the will of God. Verse 3: “This is the will of God, your sanctification; that is, that you abstain from sexual immorality.” Sexual purity is God’s will, and Christians love the will of God. Christlikeness means that we delight to do God’s will (Psalm 40:8; Hebrews 10:7).

3. The incentive of honor. Controlling your body in purity is a matter of honor — either being honored by the community or showing honor to your wife and other women, or to your husband and other men. Verse 4: “That each of you know how to possess his own vessel in sanctification and honor.” Sexual purity is the honorable thing to do.

4. The incentive of Christian love that seeks the good of others. Sexual purity is the loving way to treat others. Verse 6: “That no man transgress and defraud his brother in the matter.” When we sin sexually we are not seeking the highest good of others, neither the woman or the man we sin with, nor the person we fantasize about nor the person in the pornography, nor the spouse or parent of any of these. It is not Christian love that moves us in any of this. It is simply selfish desire. But Christians are people deeply moved by love for others. Christians love people; they don’t use them.

5. The incentive of God’s vengeance. Verse 6b: “because the Lord is the avenger in all these things, just as we also told you before and solemnly warned you.” If you turn from the Lord as your treasure and your all-satisfying pleasure, and make a master out of sex, sooner of later you will meet the wrath of God.

Far more could be said about the what of sexual purity and the why of sexual purity, but most urgent is the how of sexual purity. I turn to that now, and it will be plain that the what and the why are all woven into the how.

How Do We Fight for and Enjoy Sexual Purity in Our Lives?

If we had more time I would love to go into great detail in the nitty-gritty tactical moves you can make in the power of Christ to fight sexual impurity. I have written of them in Future Grace and in the Star (see A.N.T.H.E.M.). But what I want to do here is focus on one thing that the text focuses on, not only for the immediate rescue, but mainly for the long-term triumph over the next ten, twenty, thirty, sixty years of your life.

This central, long-term how is found in verse 5. Start reading with me at verse 4: “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.” There it is: “like the Gentiles who do not know God.” When you give way to lustful passion, you act like people “who do not know God.” This means: knowing God is the path to sexual purity. If you are struggling with sexual impurity in mind or body, the immediate and long-term strategy is know God. Know God!

“Knowing God is the path to sexual purity.”

Be careful here! Don’t nullify 1 Thessalonians 4:5 by saying with a cynical tone: “Good grief, there are world-class theologians who are in bondage to lust and who leave their wives. So what good is all this knowledge about God?” Indeed there are. And I say with tremendous confidence: they don’t know God. To know ten thousand facts about God is not to know God.

Knowing God is the path to sexual purity. And if you are in bondage to pornography and fantasies or fornication or adultery the immediate and long-term strategy of this war is: Know God! Know God! Lustful passion is the mark of the Gentiles who do not know God. (See 1 Peter 1:14; Ephesians 4:22; Romans 1:23–28.)

Why would this be? Why would God ordain that the path to sexual purity is knowing God? The answer is given in 1 Corinthians 6:18–20:

Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body.

Or verse 13: “The body is not for immorality, but for the Lord, and the Lord is for the body.” We have bodies so that God might be glorified in them. That is why God gave you a body — whether it’s tall or short, pretty or plain, brawny or feeble. This is what Paul said in Philippians 1:20: “It is my eager expectation and hope that Christ will . . . be exalted in my body, whether by life or by death.” Our bodies are given to us so that in the way we use them Christ is made to look more valuable to us than anything.

Now we can see why it is that Paul would say that knowing God is so crucial in the war on lust and pornography and fornication and adultery. If, by some means, you get rid of lustful thoughts and slavery to pornography and fornication and adultery — without any reference to the knowledge of God, he won’t get any glory for your new behavior. In other words, God is not just interested in what you do with your body, he is interested in — he is passionately concerned with — why you do it. If there is no connection between your knowing God, and your sexual purity, God gets no glory and you are in the grip of another idol.

Knowing God is the path to sexual purity because the purpose of sex and the purpose of the body is to magnify the supreme worth of God and the infinite value of Jesus Christ. And he will not be seen as supremely worthy and infinitely valuable if knowing him is not the key and the path of our liberation. “You will know the truth and the truth will set you free” (John 8:32). And Jesus said, “I am the way the truth and the life” (John 14:6). Knowing God, knowing Christ, is the path to sexual purity.

But we should ask in closing: Knowing what about him? Knowing him in what way? Let me mention three things about God that he may use to set you free and keep you free.

Know the Patience of God

Look at verse 1: “Finally then, brethren, we request and exhort you in the Lord Jesus, that as you received from us instruction as to how you ought to walk and please God (just as you actually do walk), that you excel still more.” Do you see what this says about God? It says these Christians have room for improvement — “excel still more and more.” And it says that they are pleasing God — “just as your actually do walk.” In Christ, God is not an all or nothing God. He knows our frame. He covers our sin. He is pleased with our successes through faith, and patient with our failures. So know him in his patience, all you struggling saints. Let this knowledge encourage you: you are walking in the way that pleases him — do so still more and more.

Know the Power of God

In the previous chapter, 1 Thessalonians 3:12–13, we read Paul’s prayer for the Thessalonians:

“We defeat the deceitful pleasures of lust with the superior pleasures of knowing God.”

May the Lord make you increase and abound in love for one another and for all, as we do for you, so that he may establish your hearts blameless in holiness before our God and Father, at the coming of our Lord Jesus with all his saints.

Notice: he asked Christ to establish them blameless in holiness at his coming. In other words, holiness is the work of Christ. Yes, we must pray for it, and yes, we must fight for it. But in the end, be encouraged! You are not left to yourself to win this war. Know God’s power on your behalf through Jesus Christ.

Know the Preciousness of God and the Pleasure He Is to Us

I say this because that is simply what it means to know God in Christ. God is the most valuable person in the universe. He is the sum and source of all true pleasure (Psalm 16:11; 37:4). And knowing this in our experience is what triumphs over temptation. Knowing the preciousness of God and the pleasures of his fellowship will strip pornography of its power. We defeat the deceitful pleasures of lust with the superior pleasures of knowing God. Paul said it like this: “I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord” (Philippians 3:8).

So, Bethlehem, downtown and at the north extension, alongside seeking the lost, and seeking social justice, let us be a people who seek sexual purity with all our might, by knowing the patience, the power, and the pleasures of our God and Savior, Jesus Christ. Lord, give us one pure and holy passion. Give us one magnificent obsession. Give us one glorious ambition for our lives: to know and follow hard after you (Mark Altrogge, “One Pure and Holy Passion”).