From Stone to Flesh: The Heart of the New Covenant Text: Jeremiah 31:31-34
Introduction: The Covenantal Problem
The Bible is a covenantal book. From start to finish, God deals with His people through covenants. A covenant is a solemn, binding agreement, a relationship defined by oaths and promises. God made a covenant with Adam, a covenant with Noah, a covenant with Abraham, and a covenant with Israel at Sinai. But as you read the Old Testament, you cannot escape a glaring and persistent problem. The problem was not with God. The problem was not with His covenants. The problem was with the people. The history of Israel is the history of covenant-breaking. They were a faithless bride to a faithful husband.
The covenant given at Mount Sinai was good. The law was holy, just, and good. It revealed the character of God and the nature of sin. But it was written on tablets of stone. It was external. It could command, it could demand, it could condemn, but it could not change the heart. It was like a perfect blueprint given to a bankrupt builder. The design is flawless, but the builder has no resources to build. Israel could not keep the law because their hearts were stony, rebellious, and bent toward sin. This is the great dilemma that the Old Testament sets before us. How can a holy God live in fellowship with an unholy people? How can a righteous law be fulfilled by unrighteous men?
Into this context of failure and faithlessness, Jeremiah delivers what is perhaps the most glorious promise in the entire Old Testament. It is not a promise to patch up the old system. It is not a promise of "try harder next time." It is the promise of something radically new, a divine solution to the problem of the human heart. This is not a renovation; it is a new creation. The author of Hebrews quotes this passage at length twice, making it the theological centerpiece for his entire argument that the new covenant in Christ is superior to the old. If we want to understand the gospel, if we want to understand what Jesus accomplished on the cross, we must understand this promise from Jeremiah.
The Text
"Behold, days are coming," declares Yahweh, "when I will cut a new covenant with the house of Israel and with the house of Judah, not like the covenant which I cut with their fathers in the day I took them by the hand to bring them out of the land of Egypt, My covenant which they broke, but I was a husband to them," declares Yahweh. "But this is the covenant which I will cut with the house of Israel after those days," declares Yahweh: "I will put My law within them, and on their heart I will write it; and I will be their God, and they shall be My people. And they will not teach again, each man his neighbor and each man his brother, saying, 'Know Yahweh,' for they will all know Me, from the least of them to the greatest of them," declares Yahweh, "for I will forgive their iniquity, and their sin I will remember no more."
(Jeremiah 31:31-34 LSB)
A New and Better Covenant (v. 31-32)
The prophecy begins with a declaration of a coming historical rupture, a fundamental shift in how God relates to His people.
"Behold, days are coming," declares Yahweh, "when I will cut a new covenant with the house of Israel and with the house of Judah, not like the covenant which I cut with their fathers in the day I took them by the hand to bring them out of the land of Egypt, My covenant which they broke, but I was a husband to them," declares Yahweh. (Jeremiah 31:31-32)
Notice first the divine initiative. Four times in this short passage, God says "I will." This is not a negotiated treaty between two equal parties. This is a unilateral, sovereign act of grace. God is the one who will initiate, establish, and secure this new covenant. Our hope does not rest on our ability to make promises to God, but on His ability to make and keep His promises to us.
And with whom does He make this covenant? "With the house of Israel and with the house of Judah." This is crucial. The new covenant is not a plan B that God cooked up after Israel failed. It is the fulfillment of the promises made to Israel. The Christian church is not a Gentile replacement for Israel; we are the fulfillment of Israel. Through faith in Jesus the Messiah, Gentiles are grafted into the one olive tree of God's people. If you are in Christ, you are a true child of Abraham and an heir of this promise.
Then comes the great contrast. This new covenant will be "not like the covenant" made at Sinai. What was the problem with that first covenant? God tells us plainly: "My covenant which they broke." The fault was not in the law, but in the people. The law was spiritual, but they were carnal. And yet, in the face of their spiritual adultery, God's disposition toward them was one of stunning faithfulness: "but I was a husband to them." Despite their constant unfaithfulness, He remained their faithful husband. This points us to the ultimate reality. The covenant relationship is a marriage, and God's faithfulness to His faithless bride in the Old Testament is the backdrop for the glory of Christ's faithfulness to His bride, the Church.
The Internal Revolution (v. 33)
Verse 33 gets to the very heart of what makes this covenant new. The change is not in the standard of righteousness, but in the location of that standard and the disposition of the people toward it.
"But this is the covenant which I will cut with the house of Israel after those days," declares Yahweh: "I will put My law within them, and on their heart I will write it; and I will be their God, and they shall be My people." (Jeremiah 31:33)
This is the miracle of regeneration. The law moves from tablets of stone to the tablets of human hearts. God promises to perform spiritual heart surgery. He takes out the rebellious, stony heart that hates His law and replaces it with a heart of flesh that loves His law and desires to obey it. This is what the New Testament calls being born again. The Holy Spirit changes our nature. He doesn't just give us a list of rules; He gives us a new set of "want to's." Obedience is no longer a matter of grim duty in order to earn favor, but a joyful response to grace already received.
This is why antinomianism, the idea that grace cancels out the law, is such a profound misunderstanding of the new covenant. The new covenant doesn't abolish the law; it internalizes it. God doesn't say, "I will forgive them, so now they can ignore my law." He says, "I will write my law on their hearts... for I will forgive their iniquity." Forgiveness is the foundation for a new kind of obedience, an obedience that flows from a changed heart.
Because of this internal work, the great covenant promise is finally and securely established: "I will be their God, and they shall be My people." Under the Old Covenant, this relationship was conditional on their obedience, which they failed to provide. Under the New Covenant, the relationship is secured by God's sovereign grace, which provides both the forgiveness for disobedience and the new heart for obedience.
A Regenerate Community (v. 34a)
The next promise describes the radical change in the nature of the covenant community itself.
"And they will not teach again, each man his neighbor and each man his brother, saying, 'Know Yahweh,' for they will all know Me, from the least of them to the greatest of them," declares Yahweh... (Jeremiah 31:34a)
This verse has been the source of some confusion. It certainly does not mean that the New Covenant community has no need for teachers. The New Testament is clear that Christ gives pastors and teachers to His church for its upbuilding. The point is not about the absence of teaching, but about the nature of the taught. The Old Covenant community was a mixed multitude. It was a national entity that included both believers and unbelievers. Therefore, you constantly had to exhort your neighbor, who might be bowing to Baal on the weekend, to "know Yahweh."
But the New Covenant community, in its essential nature, is a regenerate community. Everyone who is truly a member of this covenant knows God personally, inwardly, and savingly. The knowledge here is not mere head knowledge; it is the intimate knowledge of a relationship. This is the great promise of the church. While the visible church will always have tares among the wheat, its defining characteristic, its fundamental identity, is that it is composed of those who "all know Me, from the least of them to the greatest." This is a community defined not by ethnic descent, but by spiritual birth.
The Foundation of Forgiveness (v. 34b)
The final clause of the prophecy reveals the foundation upon which all these other glorious promises are built.
"...for I will forgive their iniquity, and their sin I will remember no more." (Jeremiah 31:34b)
This is the bedrock. How can a holy God write His holy law on a sinful human heart? Only after that heart has been cleansed. How can sinful men know a holy God? Only after their sin, which separates them from God, has been decisively dealt with. All the blessings of the new covenant flow from this promise of unconditional, total, and final forgiveness.
The phrase "their sin I will remember no more" is judicial language. It does not mean that the omniscient God suffers from amnesia. It means that He will never again bring our sin up against us as a charge in the courtroom of heaven. When Christ died, He paid the penalty for our sins in full. God's justice was satisfied. Therefore, when God looks at a believer, He does not see their sin; He sees the perfect righteousness of His Son. The debt has been paid, the record has been expunged, the case is closed forever.
Conclusion: Living in the New Covenant
This promise from Jeremiah is not an abstract theological point. It is the charter of our freedom and the source of our life. Jesus Himself inaugurated this covenant. At the Last Supper, He took the cup and said, "This cup is the new covenant in My blood, which is poured out for you" (Luke 22:20). The blood of Jesus Christ is what purchased every single promise in this text.
Because of this, we live in a new reality. Our relationship with God is not based on our performance, but on His promise. Our obedience to God is not a desperate attempt to earn His love, but a grateful response flowing from a heart that He Himself has changed. Our assurance does not rest in our ability to hold on to Him, but in His unbreakable promise to hold on to us.
The law is no longer our accuser, but our delight. Sin is no longer our master, but our defeated foe. And God is not a distant, angry judge, but our Father, and we are His people. This is the good news. This is the heart of the matter. This is the new covenant.