I wish I knew then what I know now about sex. I wish I could redo every adrenaline-filled step I took into romance and intimacy, and heal every wound I inflicted. I wish I would have made Jesus look real, trustworthy, and satisfying in all of my dating. Instead, it often looked like I didn’t really believe what he said, and that he wasn’t enough for me. I dated, at times, like I simply did not know God.

When I look back on those years and relationships and failures, three words immediately rise up against me: You knew better.

Not, you knew you shouldn’t do this or that, and you did it anyway. (That was true, too.) No, you knew him better. You had seen the radiance of the glory of God and the exact imprint of his nature in Jesus Christ. You had tasted the goodness of God pouring from every crevice of the cross and filling every square foot of creation. You had smelled the undeniable aroma of Christ, a smell so pleasant that it raised your lifeless body out of the grave. You had touched, by faith, the wounds that healed you. You had heard his voice, sweeter than honey and finer than the finest gold.

You knew him, Marshall. Why did so many of your decisions betray what you had seen and tasted and heard — what you knew?

Sex Without God

At its simplest, we should have sex (or not) like people who know God. Paul says, “This is the will of God, your sanctification: that you abstain from sexual immorality; that each one of you know how to control his own body in holiness and honor, not in the passion of lust like the Gentiles who do not know God” (1 Thessalonians 4:3–5).

The Gentiles — unbelievers, in the world and not in Christ — are involved in all kinds of sexual nonsense. They lose control of their lusts, dishonor their own and others’ bodies, and dive headlong into sexual immorality. None of that should surprise us too much because they don’t know God. We should expect them to go too far, and too fast — to fool around with the random person at the party, or sleep with their third or fourth person in a month, or move in with their boyfriend.

If God is out of the picture, sex can seem like as good a god as any. It will still fail them forever, but that doesn’t bother them, because they don’t believe in Jesus or sin, heaven or hell. They believe in now, in living it up here on earth as much as possible, and for as long as possible — until repentance is no longer possible.

Like We Know God

In Christ, we know better. We know that sin, death, and hell are as real as the roof over our heads, last month’s cell-phone bill, or the Grand Canyon. They’re not ideas flying around in our philosophy class. They’re realities hanging over every inch of our lives.

We live every moment in the shadow of a real Creator and a real judge, one who knows our every thought and move. We know that we deserve less than nothing because of our sin, that we’ve earned conscious, relentless, inescapable destruction for ourselves, and that “everyone who is sexually immoral or impure . . . has no inheritance in the kingdom of Christ and God” (Ephesians 5:3–5). And we know that Christ came to die — the crown of thorns, the whip filled with rocks, the nails in his hands and feet, the terrifying wrath of God — for our sin and to rescue us out of sin.

God made each of us and invented sex — why would we act like we know better than him? God warns us that sexual immorality leads to pain, shame, slavery, and ultimately judgment — why would we risk so much for a little pleasure now? God bought our forgiveness, freedom, and purity with the blood of his own Son — an infinite cost — why would we heap more sin on his shoulders and drive the nails even deeper? God waits with open arms to welcome us into a never-ending adventure of peace and happiness with him — why would we trade it away for a few seconds of satisfaction?

What We Already Know

Sadly, some of us still do. Temptation overwhelms us in moments of weakness. I knew what sexual impurity was, and does, and says, and I still fell. I did not fall simply because I did not know enough, but because I did not take what I knew with enough seriousness and joy — not yet.

Paul is saying what we already know about God is enough to keep us from sexual sin. If we have been losing and losing in the battle against temptation (any temptation), there may be a dozen important factors to consider, but the most important is this: What we know about God has not yet pierced the parts of us in bondage to this sin. Through prayer and meditation and fellowship, we need to press what we have seen and heard and tasted deeper and deeper — until it hurts (Hebrews 12:4). We need to let the desperation of failure pry open the eyes of our hearts wider to him.

To know God — his sovereign power, his surprising mercy, his sacrificial love, his satisfying friendship — is to hold the keys to sexual purity, even in a sex-crazed society. Especially in a sex-crazed society. As we set our eyes and hearts above, “the love of Christ controls us” (2 Corinthians 5:14), and more and more, we “know how to control [our] own body in holiness and honor, not in the passion of lust” (1 Thessalonians 4:4). We reject temptation like we know God.

Good Sex Is About God

Knowing God will not only help us avoid sexual sin, however. We have allowed Satan to seize far too much real estate in the bedroom. Knowing God not only arms us against him; it lights the marriage bed on holy fire. After God made the first man and woman, his words to the couple were “Be fruitful and multiply” (Genesis 1:28). Enjoy one another. Have sex like you know God. Fill the earth with the fruit of your love for each other.

If we gladly obey all that God has said about sex, within the promises of a covenant before God, he gives sex a depth the world has never known. In any given marriage, there may still be major challenges to overcome, because sex, like everything else, is part of the fabric of a sin-broken world. But if we have sex like we know God, sex is about so much more than the mechanics of intercourse. It’s about God — seeing God, hearing God, enjoying God.

As we count each other more significant than ourselves in marriage, outdoing each other in showing honor, we discover an intimacy and story so much more satisfying than all the other ways we’re tempted to use sex. We experience something better than what pornography and impurity ever promised us. Sex between a husband and a wife who know and enjoy God anticipates heaven like very few things do.

I can identify with the shame and heartache of sexual failure, and four years into marriage, I now can testify to the rare pleasure of sexual faithfulness — of having sex like we know God.