I Will Put My Laws on Their Hearts
The problem with the law is that it is always “outside” of us; that is, the law calls us from without and tells us that this is the way we ought to go. Now, it is very good that the law tells us this; otherwise, we might not know, our minds being so darkened by sin. But it can only command us; it cannot help us to go the way we ought to go. In other words, the law does not inspire and certainly does not give us a desire to obey its terms. The law bestows nothing inward to induce us to follow the right way.
But the Prophet Jeremiah preaching six-hundred years before our Lord’s birth spoke of a day when the Lord would make a new covenant with His people in which He would “put [His] law within them, and…write it on their hearts” (31:31-34). This is what the Preacher rehearses now, which he did in 8:8-12, meaning that this Old Testament passage meant much to him. And why is this? Because the Prophet speaks of that something more which we need if we are to follow the path of life. So, he speaks of an inward impulse, something that makes us want to follow God’s word. He speaks of a new heart and a new mind being created in the one who would be numbered among God’s people. We call this the “new birth,” in which we are given a heart of flesh to replace our heart of stone (Ezekiel 11:19; 36:26). The Apostle Peter says that we “have been born again, not of perishable seed but of imperishable, through the living and abiding word of God” (1 Peter 1:23).
Moreover, God gives us His Holy Spirit (1 Thessalonians 4:8), who “bears witness with our spirit that we are children of God” (Romans 8:15-16). With this new principle of spiritual life within us (the new birth) and the Holy Spirit speaking truth to the inward man, nurturing faith within us, and empowering us to kill sin and grow in grace, we have under the new covenant what the old covenant could never provide for us through legal prescriptions.
And the Preacher quotes Jeremiah quoting God, “And I will remember their sins and their lawless deeds no more,” as far from us as east is from west, the psalmist says (103:12). And this is yet another proof that our Lord’s sacrifice is once for all; after all, if one sacrifice atoned for all sin, what need is there for another sacrifice? And so we now have what we always needed—new life. God’s ways are now good and right and holy to us. We now have a desire to follow and obey, for the Lord’s ways are now beautiful to us, because He is beautiful to us. He is our heart’s and our love’s desire.