Psalm 51 is a psalm of repentance from David after his adultery with Bathsheba and the murder of Uriah. The adultery is not mentioned in the psalm at all, and of course the question is, "Well, why not?" And what follows is a clip from John Piper's sermon, "A Broken and Contrite Heart God Will Not Despise," from his June 8, 2008 sermon.

Here's what he said. "There is not a word about sex in this psalm, nor is there a word about murder, nor is there a word about lying. And it all started with sex, or did it?" No. Freud may think everything start with sex. "All my problems are sex." The Bible doesn't see it that way.

The misuse of the beautiful gift of sex is a symptom of a disease, not the disease. And that's why this psalm doesn't mention it. And it's the main issue. Or we thought it was the main issue. It's not the main issue. This is the main issue. "Restore to me the joy of your salvation, because when that joy fades, I click on pornography.

When that joy fades, I start cruising the neighborhood. When that joy fades, I get an itch for another woman. When that joy fades, on and on and on. Every sin on the outside is symptomatic of the absence of this joy. This psalmist knows how to fight." I don't have any problem doing all kinds of things to surround men and women with protections against sexual sin.

In fact, I think that's a very good idea, just not the main point. If that's where you fight the battle continually, you will never get to the root of the issue. The root of the issue here is this renewed heart, this joy and gladness, the bones that God has broken healed with the joy of our salvation.

He asked God to bring his joy to the overflow of praise. Verse 15, "O Lord, open my lips and my mouth will declare your praise." Praise is what joy in God does unless there's an obstacle that needs to be removed. And all of you have obstacles. Me too. And what he's praying is that they be removed.

"Open my lips! Come on, mouth! Get with the soul! Why do I know him? Why do I love him? And I can't say it to my wife, I can't say it to my kids, I can sing in the congregation, but I can't praise him." Why? What's wrong with us?

All kinds of obstacles. So join him, just join him in praying. "Open my lips that I may praise you." He asks that the upshot of all this will be effective evangelism. Verse 13, "Then I will teach transgressors your ways and sinners will return to you." David is not content to be forgiven.

He's not content to be clean. He's not content to be elect. He's not content to have a right spirit. He's not content to be happy by himself. He will not be content until his brokenness heals others. So many of us think, "I've got to be totally triumphant to have a witness!" This makes no sense, if that's true.

He has passed through incredible darkness and horrors morally in his life, and now he's saying, "If you could just give me a taste again of some of the joy that I once knew, all of this would result in conversions!" And it will. You think you have so blown it in your life, you cannot be used.

That's what many of you think in this room. You have so blown it that you cannot be used to make a difference for Jesus in the world. That's the devil talking. He doesn't want you to make a difference, that's for sure. And one of the reasons he helped drag you down was so that you'd think that way, and one of the reasons this is in the Bible is to nullify that lie.

So just join David in pleading, "God, I know I've messed up. Oh, I've messed up! I've killed and I've raped and my baby's dead! Would you cause people to come to Christ through my life? Maybe that would be the way the Lord would make evangelism happen at Bethlehem." Amen.

What a surprise to see missions appear in verse 13 of Psalm 51. For the full message, go to DesiringGod.org and search in John Piper's sermon archive for the title, "A Broken and Contrite Heart God Will Not Despise," the sermon preached on June 8, 2008. So what counsel would John Piper offer to a wife who's stressed and disappointed in her husband and who is considering divorce as a way of escape?

We'll ask him that very question tomorrow. I'm your host Tony Reinke, thanks for listening to the Ask Pastor John podcast.