Behold, the days are coming, says the Lord, when I will make a new covenant with the house of Israel and with the house of Judah—not according to the covenant that I made with their fathers in the day that I took them by the hand to lead them out of the land of Egypt, My covenant which they broke, though I was a husband to them, says the Lord. 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 minds, and write it on their hearts; and I will be their God, and they shall be My people.
The new covenant is the covenant of grace. The legal covenant demanded of man what the unrenewed person could not give—perfect righteousness—implicit obedience to the holy law of God as a ground of blessing. It is epitomized in the words, “Which if a man does, he shall live by them” (Leviticus 18:5). But it contained the solemn warning, “Cursed is the one who does not confirm all the words of this law” (Deuteronomy 27:26). Because all were disobedient, all found it to be a ministration of death and condemnation (2 Corinthians 3:7, 9). If it could have given life to dead sinners, it would then have produced righteousness, as Paul tells us in Galatians 3:21.
But God used the law to show men their need of His grace because of their own utter sinfulness and their helpless condition. This grace is revealed in the new covenant.
As debtors to mercy alone,
Of heavenly mercy we sing;
Nor fear to draw near to the throne,
Our person and off’rings to bring:
The wrath of a sin-hating God
With us can have nothing to do;
The Saviour’s obedience and blood
Hide all our transgressions from view.
The work which His goodness began,
The arm of His strength will complete;
His promise is Yea and Amen,
And never was forfeited yet:
Things future, nor things that are now,
Nor all things below nor above,
Can make Him His purpose forego,
Or sever our souls from His love.
H. A. Ironside, The Continual Burnt Offering: Daily Meditations on the Word of God (Neptune, NJ: Loizeaux Brothers, 1994), 123.