Jeremiah 31:31–34 is perhaps the single most important Old Testament passage for understanding the New Covenant - and it is also the passage most frequently misused by the Hebrew Roots Movement. The HRM claim is straightforward: the law written on the heart in the New Covenant is the Mosaic Torah. The New Covenant does not replace Torah observance, it merely internalises it. Believers still keep the Sabbath, the feasts, the dietary laws, and the full 613 commandments - but now from the heart rather than merely as external compliance.

It is a coherent-sounding argument. But it does not survive contact with the text itself - or with reality.

If you have not yet read the two preceding articles in this series - Why Then the Law? and Circumcision of the Heart - they provide essential background for what follows. This article builds directly on both.

The Passage Itself

"Behold, the days are coming, declares the Lord, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant that I made with their fathers on the day when I took them by the hand to bring them out of the land of Egypt, my covenant that they broke, though I was their husband, declares the Lord. For this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my law within them, and I will write it on their hearts. And I will be their God, and they shall be my people. And no longer shall each one teach his neighbour and each his brother, saying, 'Know the Lord,' for they shall all know me, from the least of them to the greatest, declares the Lord. For I will forgive their iniquity, and I will remember their sin no more." (Jeremiah 31:31–34)

The HRM reads verse 33 - "I will put my law within them" - and concludes that "my law" means the Mosaic Torah in its entirety. From this reading they build a comprehensive case for ongoing Torah observance as the framework of New Covenant life. But the text, read carefully and honestly, resists this interpretation at every point.

Argument One: "Torah" Is Not a Technical Term for 613 Commandments

The Hebrew word torah means instruction, teaching, or guidance. It is a broad term. While it is used to describe the Mosaic legislation, it is not exclusively a technical reference to the Sinai covenant code. It is used in Proverbs for a mother's teaching (Proverbs 1:8), in Isaiah for God's broader instruction to the nations (Isaiah 2:3), and in contexts that have nothing to do with the Mosaic covenant specifically.

When God says through Jeremiah "I will put my torah within them," importing the full 613 Mosaic commandments into that word is an assumption driven by a prior theological commitment, not by the text itself. The reader must ask: which instruction? Whose law? And the rest of the passage - as we will see - answers that question clearly.

At this point the Hebrew Roots Movement often introduces a hermeneutical argument: the original readers of Jeremiah - first-century Jews steeped in the Torah - would have understood torah to mean the Law of Moses without question. Who are we, centuries later, to impose a different meaning on a word they already knew perfectly well?

It sounds like a principled argument for textual fidelity. It is not. What it actually does is elevate the assumptions of the original human audience above the intention of the divine author - and that is a hermeneutical error with serious consequences. Sound interpretation has always recognised that what people heard is not the same as what God meant, and that later revelation is authorised to clarify, expand, and even correct the assumptions of earlier readers.

A powerful Old Testament example makes this unmistakably clear. In Psalm 16:10, David writes: "You will not abandon my soul to Sheol, or let your Holy One see corruption." The original readers of this psalm almost certainly understood it as a statement of David's personal confidence in God's protection - a poetic expression of trust that God would not let him die prematurely or be forgotten. That is what a first-century Jewish reader would have "known" the text meant. And yet when Peter stands up on the day of Pentecost and quotes this exact verse, he explicitly overrules that reading: "Brothers, I may say to you with confidence about the patriarch David that he both died and was buried, and his tomb is with us to this day. Being therefore a prophet… he foresaw and spoke about the resurrection of the Christ, that he was not abandoned to Sheol, nor did his flesh see corruption." (Acts 2:29–31)

Peter's argument is direct: what the original readers assumed the text meant - a general statement about David - was not what the Spirit intended. The text carried a meaning its first audience did not and could not fully perceive. The original readers' understanding is the floor of interpretation, not the ceiling. And the same Spirit who moved Jeremiah to write about a new covenant was not limited by what his contemporaries assumed the word torah meant.

The HRM argument from original audience understanding, applied consistently, would also prevent us from seeing Christ in Isaiah 53, the resurrection in Psalm 16, or the universal mission in Isaiah 49. It is a principle that, if followed honestly, dismantles the entire New Testament's reading of the Old - which is precisely why it cannot be the foundation of sound interpretation.

Argument Two: The Text Explicitly Says "Not Like" Sinai

This is the argument that should end the discussion before it begins - and yet it is consistently passed over in HRM teaching with remarkable speed. Verse 32 says the new covenant will be "not like the covenant that I made with their fathers" when God brought Israel out of Egypt. That covenant - the one made at Sinai, the Mosaic covenant - is explicitly identified as the thing the new covenant will not be like.

If the law written on the heart in the new covenant were identical to the Mosaic Torah, the new covenant would be exactly like the Sinai covenant - just delivered differently. But God says it will not be like it. The difference is not merely the delivery mechanism. Something genuinely new is being introduced. The HRM interpretation collapses the very distinction the text is at pains to establish.

Argument Three: No Mediating Class - Incompatible with Mosaic Structure

Verse 34 contains a statement that is structurally incompatible with the Mosaic system: "No longer shall each one teach his neighbour and each his brother, saying, 'Know the Lord,' for they shall all know me, from the least of them to the greatest."

The Mosaic covenant required an entire apparatus of mediation: priests, Levites, scribes, teachers of the law. Knowledge of God under Sinai was transmitted through an institutional structure. The whole point of having a Levitical class was precisely to teach the people the law and maintain the covenant. Deuteronomy is saturated with instructions about teaching the law to your children, to your neighbours, to the next generation.

But Jeremiah 31 describes a covenant under which that entire mediating structure becomes unnecessary - because every member of the covenant community will know God directly, from the least to the greatest. This is not a description of the Mosaic system internalised. It is a description of something the Mosaic system was structurally incapable of producing.

Argument Four: "I Will Remember Their Sin No More"

The climax of the passage is the promise of complete and final forgiveness: "I will forgive their iniquity, and I will remember their sin no more." The Mosaic sacrificial system could never say this. The author of Hebrews is explicit: "In these sacrifices there is a reminder of sins every year. For it is impossible for the blood of bulls and goats to take away sins." (Hebrews 10:3–4)

The annual Day of Atonement was not a final settlement. It was a deferral - a yearly acknowledgment that the account was still open. The new covenant closes the account permanently. "I will remember their sin no more" describes a once-for-all forgiveness that the entire Mosaic sacrificial machinery was specifically designed not to provide - because it was pointing forward to something that would.

If the new covenant were simply the Mosaic Torah written on the heart, this promise of permanent and unrepeatable forgiveness would make no sense. It belongs to a different kind of covenant entirely.

Argument Five: Hebrews Quotes Jeremiah 31 and Concludes "Obsolete"

The author of Hebrews - writing to a Jewish-Christian audience deeply formed by the Torah - quotes Jeremiah 31:31–34 at length in Hebrews 8, and then draws this conclusion: "In speaking of a new covenant, he makes the first one obsolete. And what is becoming obsolete and growing old is ready to vanish away." (Hebrews 8:13)

This is the most authoritative New Testament interpretation of Jeremiah 31, and it directly contradicts the HRM reading. If the new covenant were simply the Mosaic Torah internalised, the author of Hebrews could not possibly have concluded that Jeremiah's prophecy made the Sinai covenant obsolete. The very act of announcing a new covenant, he argues, implies the inadequacy and impending end of the old one.

The HRM must either accept this interpretation - in which case their position collapses - or reject Hebrews as a reliable guide to understanding Jeremiah. Many HRM teachers quietly do the latter, treating Hebrews with suspicion or marginalising its argument. But that is a significant concession to have to make.

Argument Six: The Tallit Problem - The HRM's Most Embarrassing Contradiction

This is where the HRM interpretation does not merely fail theologically. It fails practically, visibly, and - it must be said - rather entertainingly.

The HRM claim is that under the New Covenant, the Holy Spirit writes the Mosaic Torah on every believer's heart at conversion. If this is true, the implications are straightforward. A new believer, the moment the Spirit takes up residence, should begin to feel the inward pull of the full Torah. Not just the moral commands - those are written on every human heart according to Romans 2:15 - but the distinctively Mosaic commands. The covenant-specific ones. The ones that marked Israel as a distinct people under Sinai.

So: does the newly converted believer in Christ spontaneously feel the need to wear tzitzit - the fringes commanded in Numbers 15:38? Do they wake up instinctively knowing not to plant tomatoes next to potatoes, as Leviticus 19:19 prohibits mixing crops? Do they feel an immediate inward conviction about the prohibition on mixing linen and wool in a single garment (Deuteronomy 22:11)? Do they reach, unprompted, for a Jewish calendar to calculate the new moon festivals?

The answer, in every case and without exception, is no. It has never happened. Not once in the history of Christian conversion has a new believer spontaneously and independently discovered the agricultural purity laws of Leviticus through the inner witness of the Spirit.

And this is not a trivial observation. It is a direct empirical test of the HRM's own claim. If the Spirit writes Mosaic Torah on the heart at conversion, the evidence should be visible in the lives of new believers who have not yet been taught. Instead, what new believers consistently and universally report is a deepened sense of the moral law - the wrongness of lying, the pull toward generosity, the guilt of lust, the call to forgive. Which is exactly what you would expect if the Spirit is writing God's moral character on the heart, rather than the Mosaic covenant code.

There is a further irony that deserves to be stated plainly. HRM communities are among the most heavily teaching-oriented religious environments you will find anywhere. New members are given reading lists. They attend Torah portions. They sit under hours of instruction about which days to observe, which foods to avoid, which garments to wear, which festivals to keep. The entire apparatus of HRM community life is built around teaching people the Torah they apparently already have written on their hearts.

But Jeremiah 31:34 says: "No longer shall each one teach his neighbour and each his brother, saying, 'Know the Lord.'" The HRM's own practice is the most eloquent possible refutation of their own interpretation of the passage. If the Torah were genuinely written on the heart by the Spirit at conversion, the Torah classes would be unnecessary. The fact that they are considered absolutely essential tells you everything you need to know about what the Spirit is actually writing - and what he is not.

But there is a second contradiction that is equally telling. If the Spirit is writing the full Mosaic Torah on every believer's heart at conversion - clearly, uniformly, and personally - then Spirit-filled believers should arrive at consistent interpretations of key passages without external instruction. There should be one reading of Galatians 4. One reading of Colossians 2:16. One reading of Romans 14. The internal witness of the Spirit, writing the same Torah on every heart, should produce agreement.

Instead, as we have already seen in this very article, the Hebrew Roots Movement offers four competing interpretations of Galatians 4 alone - legalism, Pharisaic tradition, Jewish conversion, obscure rabbinic allegory. Teachers within the movement disagree with each other significantly on which Torah commands apply, in what form, and with what authority. There are heated debates about calendar systems, about which feast dates are correct, about whether Gentile believers must be circumcised, about whether Paul can be trusted at all.

This is not what an internally written, Spirit-confirmed Torah looks like. This is what happens when people are working from external sources - books, teachers, traditions, competing interpretations - trying to reconstruct a system that the New Covenant never asked them to reconstruct. The disunity within the HRM is not incidental. It is diagnostic. It is precisely the kind of fragmentation you would expect from a movement built on external law-keeping - and precisely the opposite of what Jeremiah 31 promises the New Covenant will produce.

So What IS the Law Written on the Heart?

If the law of Jeremiah 31 is not the Mosaic Torah code, what is it? The answer emerges from the context of the whole prophetic tradition and the New Testament's own interpretation.

It is the moral character of God - his justice, his faithfulness, his love, his holiness - written not on stone tablets external to the person but inscribed by the Spirit within the person, producing genuine and spontaneous conformity to God's nature. It is what Paul describes in Romans 8:4 as "the righteous requirement of the law fulfilled in us who walk according to the Spirit." It is what Jesus summarises in Matthew 22:37–40 as love for God and love for neighbour - the two commands on which "all the Law and the Prophets hang."

It is not a legal code requiring external instruction to implement. It is a transformed nature producing from within what no external code could ever produce from without. It is the answer to what Moses longed for in Deuteronomy 30, what Jeremiah mourned the absence of, and what Ezekiel prophesied God would one day sovereignly accomplish by replacing the heart of stone with a heart of flesh.

That work has been done. In Christ. Through his Spirit. For all who believe.

I will put my law within them, and I will write it on their hearts. And I will be their God, and they shall be my people. - Jeremiah 31:33