Jeremiah 31:31-34, Luke 22:20, Hebrews 8:6-13
The Most Important Covenant Prophecy
"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).
This is the only place in the entire Old Testament where the phrase "new covenant" appears — and the New Testament builds massively on it.
What the New Covenant Promises
Four elements distinguish the new covenant from the Mosaic:
Internalised law — written on the heart, not on tablets of stone. The problem with the Mosaic covenant was not the law but the people — their hearts were stone. The new covenant promises transformed hearts that genuinely desire obedience (Ezekiel 36:26-27 adds: "I will put my Spirit within you, and cause you to walk in my statutes").
Direct knowledge of God — no longer mediated through a priestly class but available to all, "from the least to the greatest." Every believer has direct access to the Father through Christ.
Full and final forgiveness — "I will remember their sin no more." Not the annual covering of sins through the sacrificial system, but their definitive removal.
The Fulfilment
At the Last Supper: "This cup is the new covenant in my blood." (Luke 22:20). At Pentecost: the Spirit poured out on all flesh (Acts 2:17-18), writing the law on hearts of flesh. Hebrews 8 quotes Jeremiah 31 in full and declares: "In speaking of a new covenant, he makes the first one obsolete." The promise is kept; the covenant is inaugurated; it awaits its final consummation.