Is the Christian's heart deceitfully wicked? You've heard that phrase, "deceitfully wicked" from the Old Testament, but is such an indictment actually applicable to the regenerated Christian heart? The question is from a podcast listener named Micah. "Pastor Jon, hello. I was recently in a debate with a friend over Jeremiah 17.9.

The heart is deceitful above all things and desperately sick. Who can understand it? I applied it to the ongoing sin blindness in the heart of the Christian. My friend said I was taking a passage about unbelieving hearts and misapplying it to the Christian heart. However, in returning to the bigger context of Jeremiah 17 verses 5-13, I find myself even more convinced verse 9 is equally applicable to believers, especially in light of verses 7 and 8.

What do you think? Is Jeremiah 17.9 about believers, unbelievers, or both? Pastor Jon, how would you process this text and this context? Let me walk quickly through the flow of thought from verse 1 of Jeremiah 17 down through verse 9, and I think everybody will be able to see how the verse is functioning if we do that, how verse 9 is functioning.

Jeremiah begins with an indictment of Judah and a warning of destruction. It says, "The sin of Judah is engraved on the tablet of their heart while their children remember their altars and their asherim." Those are other gods, so idolatry is the issue here. "Your wealth and all your treasures I will give as spoil and as a price of your high places for sin." So he's going to bring judgment upon them for the sin of their heart and the idolatry of their worship.

And then he says what's beneath that. He says in verse 5, "Cursed is the man who trusts in man and makes the flesh his strength, whose heart turns away from the Lord. He is like a shrub in the desert and shall not see any good come." Now, that's the root problem of the idolatry and the sin.

The root problem is they are trusting in man, not in God. And then he describes what alternatively ought to be the opposite of this and the benefits that would come if it were the case. Blessed is the man—not cursed is the man who trusts in man—but blessed is the man who trusts in the Lord, whose trust is in the Lord.

He's like a tree planted by water that sends out its roots by the stream and does not fear when heat comes, for the leaves remain green. And he's not anxious in the year of drought, for it does not cease to bear fruit. Now, that leaves us with this question.

Well, if trusting in self results in such misery, "no good shall come," and trusting in God results in such fruitfulness, you can prosper. Why in the world is a whole nation acting so suicidally in self-trust and sin and idolatry? And his answer is verse 9, "The heart is deceitful above all things, and desperately sick who can understand it." So the human heart is diseased with sin and in the sway of deceit, and that's why people act suicidally in preferring self-trust over God-trust.

So the overall point of the passage seems to be that the root of sin and idolatry is a failure to trust in God rather than self, and the root of that failure is a deceitful and depraved heart. So I think Jeremiah—indeed, I think all the biblical writers—would say that's the root problem ever since the fall of man into sin and corruption.

All human beings, no exceptions, are born with this kind of fallen, diseased, deceived, self-exalting, God-opposing heart. So the question is, when a person experiences the new birth, becomes a Christian, what happens to that diseased, deceived, self-exalting, God-opposing heart? And here are some verses that describe what happens. So Ezekiel 36, the new covenant, described like this, "I will give you a new heart and a new spirit I will put within you, and I will remove the heart of stone from your flesh and give you a heart of flesh." Or Romans 6:17, "Thanks be to God that you who once were slaves of sin have become obedient from the heart to the standard of teaching to which you were committed." Or Acts 15:9, "God made no distinction between Jew and Gentile, having cleansed their hearts by faith." Or John 7:38, "Whoever believes in me," Jesus says, "as the Scripture has said, out of his heart will flow rivers of living water." Oh, amazing!

I want to be like that, right? I just want to have a kind of new heart that doesn't just enjoy water, it flows to other people. So I'm going to read the next verse now, John 7:39, "Now this he said about the Spirit, whom those who believed in him were to receive." Or 1 Timothy 1:5, "The aim of our charge is love that issues from a pure heart." Or 2 Corinthians 5:17, "If anyone is in Christ, he's a new creation." So my conclusion is that we can say that Jeremiah 17:9, "Deceitful above all things and desperately sick," the human heart, is true of the human heart, all of them.

But that where God is applying the blood-bought purchase of the new covenant, there is a new creation. Sins are forgiven, Holy Spirit is poured in, new nature is brought into being. That newness consists in the presence of the heart influencing Holy Spirit and in the new nature—you might call it the divine-like DNA—that is more and more being conformed to Christ.

So maybe a good verse to end on would be 2 Corinthians 3:18, "Beholding the glory of the Lord, we are being," I would say this old, horrible, self-exalting, God-opposing heart of mine, "is being transformed into the same image from one degree of glory to another." Really good and careful exegesis of these Old Testament texts and of key New Testament texts as well.

Thank you, Pastor John, for putting this all together for us. And thank you for listening. If you haven't done so, you can get the latest episodes by subscribing to Ask Pastor John in your favorite podcast app in Spotify or by subscribing to DG's YouTube channel. To find episodes in our archive or to submit a question of your own to us, go online to DesiringGod.org/AskPastorJohn.

We are going to return on Wednesday. I am not certain of the topic, but we'll see you then. I'm Tony Reinke. Thank you for listening to the Ask Pastor John podcast with longtime author and pastor John Piper. We'll see you Wednesday.