What does Jeremiah mean that the heart is deceitful?

Question 6019.

Jeremiah 17:9 says the heart is deceitful above all things, and the doctrine of the deceitful heart has been used to prove a great deal that Jeremiah never said. It has been quoted to shut down every intuition, every emotion and every conviction a believer has ever had.

That is not what the verse is doing. Let me put it back in its own setting and see what it actually claims.

What the verse says in its own context

The full sentence runs: the heart is deceitful above all things, and desperately sick; who can understand it (Jeremiah 17:9-10)? Immediately afterwards God says that He searches the heart and tests the mind, to give every man according to his ways.

The context is a contrast between the man who trusts in man and makes flesh his strength, who is like a shrub in the desert, and the man who trusts in the Lord, who is like a tree planted by water. The deceitful heart is the reason the first man cannot see that he has chosen the desert.

So this is not a stray insult about human emotion. It is the explanation for a specific failure of judgement, namely the persistent human ability to arrange life away from God and feel entirely reasonable while doing it.

The Hebrew is sharper than the English

The word for heart is lev, which in Hebrew covers far more than feeling. It is the seat of thought, will, memory, conscience and desire, the whole inner control room of a person. When the Bible speaks of the heart it usually means what we would call the self.

The word rendered deceitful is related to the name Jacob, the heel grabber, the supplanter. It carries the sense of something twisted, crooked, that trips you up. The picture is not of a heart that lies to other people but of a heart that outmanoeuvres its owner.

And desperately sick translates a term used elsewhere of an incurable wound. Jeremiah is describing a condition that will not respond to treatment from within the patient, which is precisely why the next verse hands the diagnosis to God.

Self deception is what a deceitful heart does best

The genius of the deceitful heart is that it does not feel deceitful. Nobody experiences their own rationalisation as rationalisation. We experience it as good sense, as balance, as being realistic about our situation.

Watch it work. A man does not tell himself he is being greedy; he tells himself he is being responsible. A woman does not tell herself she is nursing bitterness; she tells herself she is being careful about who she trusts. The label is always flattering, and the label is always the first lie.

That is why Scripture insists on outside light. Paul says he is not aware of anything against himself, but he is not thereby acquitted, and it is the Lord who judges him (1 Corinthians 4:4). If Paul would not trust his own audit, I am not going to trust mine.

Does this apply to Christians?

Jeremiah is describing fallen humanity, and the believer has been given a new heart. Ezekiel promises exactly that, a heart of flesh in place of a heart of stone, and the New Covenant writes the law on the heart. Something real has changed at conversion and I will not undersell it.

What has not yet changed is the presence of the flesh, the fallen inclination that remains and opposes the Spirit. So the believer is not defined by the deceitful heart, but neither is he immune from its habits. Paul assumed the Corinthians could deceive themselves and warned them repeatedly about it.

The practical upshot is that a Christian should hold his own self assessment loosely. Not with despair, and not with suspicion of every good impulse, but with the humility of someone who knows the instrument is not perfectly calibrated. More on this in the article on whether we can trust our hearts.

This is not a ban on the inner life

Some teaching takes this verse and effectively forbids believers from having feelings, instincts or desires. That is a misuse. The same Bible tells us to delight in the Lord, to rejoice, to grieve with those who grieve and to let the peace of Christ rule in our hearts.

Desires are not automatically suspect. God gives good desires, the Spirit produces affections, and much of the Psalter is emotion offered to God without apology. A deceitful heart does not mean every feeling is a lie; it means no feeling is self authenticating.

The correct response is not to silence the inner life but to submit it. Test everything, hold fast to what is good. That is a workable discipline. Distrusting yourself into paralysis is not.

Ask to be searched

David’s prayer is the right response to Jeremiah’s diagnosis. Search me, O God, and know my heart; try me and know my thoughts, and see if there be any grievous way in me (Psalm 139:23-24). He asks for the examination he cannot perform.

God has provided the means. Scripture is living and active, piercing to the division of soul and spirit, discerning the thoughts and intentions of the heart. It reads us while we are reading it, which is why regular exposure matters more than clever technique.

He has also provided people. A church where believers know each other well enough to ask uncomfortable questions is a standing remedy for the deceitful heart. Isolation is the natural habitat of self deception.

The remedy is a new heart, not better effort

Notice that Jeremiah does not follow the diagnosis with advice. He does not say try harder, examine yourself more rigorously or keep a stricter diary. The wound is incurable from the inside, and that is the whole point of the verse.

The answer comes later in the same book, in the promise of a covenant in which God writes His law on the heart and forgives iniquity and remembers sin no more. That promise is fulfilled in Jesus, and the Spirit who indwells the believer is the guarantee of it.

So the doctrine of the deceitful heart ends not in cynicism about people but in dependence on God. I cannot trust myself. I can trust Him, and He has given me His Spirit precisely because He knows what I am like.

How a deceitful heart handles Scripture

One of the more uncomfortable observations in pastoral work is how readily the Bible itself can be recruited into self justification. A deceitful heart is perfectly capable of finding a verse that supports the decision it had already made, and of skimming past the paragraph that would have unsettled it.

Jeremiah’s own generation did precisely that. They had the temple, the sacrifices and the slogan, and they repeated it as a charm: this is the temple of the Lord, the temple of the Lord, the temple of the Lord (Jeremiah 7:4). Their orthodoxy was intact and their lives were not, and they could not see the gap.

The safeguard is reading widely rather than selectively, letting Scripture set the agenda instead of answering the questions we bring, and staying under teaching we did not choose. A diet composed entirely of favourite passages will confirm us in whatever we already are.

Not cynicism about people

This doctrine has occasionally been turned into a general suspicion of human beings, as though the right posture towards everyone is mistrust. That is not what Jeremiah is doing, and it does not describe how the New Testament tells believers to treat each other.

Love believes all things and hopes all things. The same Paul who refused to trust his own audit tells the Corinthians that love is not resentful and does not keep a record of wrongs. Realism about the human capacity for self deception should make me patient with others, not sour.

In practice, knowing my own heart is the best cure for harshness about yours. The man who has caught himself in three rationalisations before breakfast is not well placed to be scandalised by anyone.

Living with a heart you cannot fully audit

It would be simpler if we could see ourselves clearly. We cannot, and the Christian life has to be lived with that limitation rather than in denial of it. Who can understand it, Jeremiah asks, and he leaves the question standing because there is no human answer to it.

What follows is not paralysis but dependence. I make the best judgement I can, I check it against Scripture, I take counsel, I act, and I hold the outcome before God who alone reads the whole file. That is not a weak way to live. It is the only honest one.

And there is comfort in it. The One who searches the deceitful heart is not shocked by what He finds there, because He knew before He saved me. Nothing He uncovers this year will cause Him to reconsider.

So, now what?

Build the outside light into your week. Read Scripture with the expectation that it will contradict you sometimes, and let one or two people have permission to say the hard thing. Both are inconvenient. Both work.

When you catch yourself constructing an unusually reasonable explanation for something you would question in someone else, slow down. That reasonableness is often the deceitful heart doing its best work. The conscience is a real gift here, and I have written about how it functions in the article on the conscience.

And pray David’s prayer occasionally, meaning it. If you want to know what is really going on inside you, ask the only person who can see it, and then be prepared for Him to answer.

The heart is deceitful above all things, and desperately sick; who can understand it? I the LORD search the heart and test the mind, to give every man according to his ways.

Jeremiah 17:9-10 (ESV)