Jeremiah 31:30-40: a reflection

30But everyone will die for his own iniquity. Every man who eats the sour grapes, his teeth will be set on edge. 31“Behold, the days come,” says the LORD, “that I will make a new covenant with the house of Israel, and with the house of Judah, 32not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt, which covenant of mine they broke, although I was a husband to them,” says the LORD. 33“But this is the covenant that I will make with the house of Israel after those days,” says the LORD: “I will put my law in their inward parts, and I will write it in their heart. I will be their God, and they shall be my people. 34They will no longer each teach his neighbor, and every man teach his brother, saying, ‘Know the LORD;’ for they will all know me, from their least to their greatest,” says the LORD, “for I will forgive their iniquity, and I will remember their sin no more.” 35The LORD, who gives the sun for a light by day, and the ordinances of the moon and of the stars for a light by night, who stirs up the sea, so that its waves roar— the LORD of Armies is his name, says: 36“If these ordinances depart from before me,” says the LORD, “then the offspring of Israel also will cease from being a nation before me forever.” 37The LORD says: “If heaven above can be measured, and the foundations of the earth searched out beneath, then I will also cast off all the offspring of Israel for all that they have done,” says the LORD. 38“Behold, the days come,” says the LORD, “that the city will be built to the LORD from the tower of Hananel to the gate of the corner. 39The measuring line will go out further straight onward to the hill Gareb, and will turn toward Goah. 40The whole valley of the dead bodies and of the ashes, and all the fields to the brook Kidron, to the corner of the horse gate toward the east, will be holy to the LORD. It will not be plucked up or thrown down any more forever.”

In one of the mountaintop promises of the Old Testament, God announces a new covenant, unlike the old one Israel had broken. This time, he says, 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. No longer will the law be merely external, written on stone and often disobeyed; it will be written inwardly, on the heart. And the covenant comes with a stunning promise of grace: I will forgive their iniquity, and I will remember their sin no more.

Notice the two great promises of this new covenant: an inward transformation, and full forgiveness. God promises not merely to give commands from outside, but to change the heart from within, writing his law on it, so that obedience flows from a transformed inner life. And he promises to forgive completely, to remember our sin no more, wiping the record clean. This is the covenant fulfilled in Christ, whose blood is the blood of the new covenant, who gives the Spirit to write God's law on our hearts and who secures the forgiveness God promised.

That promise is the heart of the gospel we live under. We are not left merely trying to obey an external law in our own strength; God works within us, writing his law on our hearts, changing us from the inside. And our sins are not merely covered but forgiven, remembered no more. If you are weary of trying to be good by sheer external effort, or burdened by the memory of your sins, hear the new covenant promise. God gives an inward transformation, not just outward rules, and a full forgiveness that remembers your sin no more. Rest in the new covenant sealed by Christ: his law written on your heart, and your sin remembered no more.

Lord, you promised a new covenant, to write your law not on stone but on the heart, to be our God and make us your people, and to forgive our iniquity and remember our sin no more. Thank you that this covenant is fulfilled in Christ, whose blood sealed it, and whose Spirit writes your law within me. When I am weary of trying to be good by external effort alone, work within me, changing my heart, so that obedience flows from a transformed life. And when I am burdened by the memory of my sins, remind me of your promise to remember them no more. Let me rest in the new covenant: your law written on my heart, and my sin remembered no more. Thank you for so great a grace.