Jeremiah spent forty years preaching to a nation that would not listen. He watched the temple fall. He outlived the kings who jailed him. And somewhere in the middle of that heartbreak, he wrote the most hopeful sentence in the Old Testament: the days are coming.
Walter Kaiser Jr. calls Jeremiah’s new covenant teaching the heart of Old Testament theology itself. Not its moral core. Not its first revelation. Its heart — the part that pumps the rest. What the patriarchs had been promised from afar, what the Mosaic covenant had exposed as unsustainable from within, what the prophets had been pointing toward — all of it converges on a single promise: I will put my law in their minds and write it on their hearts. The covenant moves from stone to flesh. From outside to inside. From something you had to keep to something God puts in you.
“A New Covenant”
The heart of Old Testament theology and of the message of Jeremiah was his teaching on the new covenant in Jeremiah 31:31–34.
The new covenant is not a different promise. It is the same promise delivered differently. The Abrahamic covenant was a person making a pledge to a person — I will be your God. The Sinai covenant was the people responding — we will be your people. And the Sinai covenant failed on the human side, not the divine side. So God promised something the human side could not break: a covenant where the terms would be written not on tablets but on hearts. A covenant he himself would keep on both sides.
That is why Messiah at the “Last Supper” (at Passover) raised the cup and called it the new covenant in his blood. He was not starting something new. He was finishing what Jeremiah saw in the dark. The covenant God would keep on both sides cost him his Son. And the promise is no longer future — “the days are coming” became “this is my blood” became “I will remember their sins no more.” What Jeremiah glimpsed in weeping, we now live in the open.
The old way to relate to God is to perform. Try harder. Be better. Check the boxes. Hope the ledger tips in your favor before the audit. This way is exhausting not because God is hard on you, but because it was never going to work. A covenant you have to keep was never going to hold your life together.
The new covenant is the one God keeps-it isn’t time bound – it is effective. Your job is not to earn it; your job is to receive it. The law that used to be outside you, accusing you, is now inside you, leading you. When you obey (hear and believe) now, you are not paying God off. You are walking the way the Spirit is already walking inside you – you have the outlook of the Spirit not the flesh (see the Net translation of Romans chapter 8 – very helpful- for example “Romans 8:5: Those who live according to the Spirit have their outlook shaped by the things of the Spirit.”). That is not a heavier yoke. That is a lighter one.⁶³
Where in your life are you still relating to God as a contractor completing tasks rather than a child receiving a gift — and what would it look like to let the covenant do its work on you?
Someone in your life is keeping score with God. They may never say it. But they are adding up the wins and the losses and hoping the math turns out. That person needs to hear that the gospel is not a scoring system. It is a covenant — and it is one they did not negotiate and cannot break.
The conversation to have is not about their behavior. It is about the covenant they do not yet know is theirs. Tell them what Jeremiah saw. God did not write the new contract on their performance. He wrote it on his own Son. And the pen he used will never run out of ink.⁶⁴
Who in your life is still keeping score with God — and what would it look like to show them the contract is already signed in blood?
The household of disciple-makers trains people to live from the covenant, not toward it. That is the one thing that turns obedience into joy. When the people you disciple understand that the law has been written on their hearts — that the Spirit is already inside them, teaching them — they stop trying to find God’s will and start noticing it was there all along.
Teach them Jeremiah 31 like it is their inheritance, because it is. Teach them that the new covenant is not an upgrade to the old one but its intended destination. Teach them to stop checking their work and start trusting the work that has been done. That is how a household learns to breathe.
What are you still trying to earn from God that he has already promised to put inside you?
Write out Jeremiah 31:31–34 slowly. Then write beside each promise what it would change about your life this week if you really believed it was yours.
⁶² Walter C. Kaiser Jr., The Promise-Plan of God (Grand Rapids: Zondervan, 2008), Chapter 9: The Prophetic Era.
⁶³ “The Fruit of the Spirit: Faithfulness,” vimeo.com/kathykoch.
⁶⁴ “Power Phrase: You Are vs. You Were,” vimeo.com/kathykoch.