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. (Jer. 31:33)
The cornerstone of the covenant that God made with the children of Israel in the desert of Sinai was the Ten Commandments. God wrote that document into tablets of stone with His own finger (Ex. 31:18). But the cornerstone of the new covenant is the living Word of God, the Lord Jesus Christ Himself (Eph. 2:19–22), who comes to live in our hearts when we first put our trust in Him (Eph. 1:13–14). When Jesus comes to live in our hearts, He indelibly writes His passions and desires (and everything else about Himself) onto our hearts, and we become full-fledged partakers of the new covenant.
Said another way, God anchored the old covenant by writing His laws onto tablets of stone, but He anchored the new covenant by indelibly writing Himself onto the fleshly tablets of our hearts. Speaking of this gigantic difference between the old and new covenants, the apostle Paul wrote:
Clearly you are an epistle of Christ, ministered by us, written not with ink but by the Spirit of the living God, not on tablets of stone but on tablets of flesh, that is, of the heart. (2 Cor. 3:3)
The way we live godly lives is much different now with Jesus living in our hearts than it was when mankind only had written commandments to obey. Before Jesus took up residence in the hearts of men, the paradigm for godly living was that the people of God should hide God’s Word in their hearts as a hedge against sin. The psalmist wrote:
Your word I have hidden in my heart,
That I might not sin against You. (Ps. 119:11)
And the proverb reads:
Keep my commands and live,
And my law as the apple of your eye.
Bind them on your fingers;
Write them on the tablet of your heart. (Prov. 7:2–3)
The reasoning, of course, was that with God’s Word on their lips and in their minds, they would have ample resources to live uprightly in challenging times. They also expected the opposite to be true. When they did not hide God’s Word in their hearts, they expected to be less successful at resisting sin than if they had done so.
This paradigm was good as far as it went, but it was weak because it did not fix the root cause of their problem. Their hearts were deceitful and desperately wicked (Jer. 17:9). No amount of Scripture memorization was enough to stop their sins (1 Kings 8:46–53). Instead of being loyal to God, they rebelled against Him repeatedly (Isa. 1:2–4).
But with Christ in our hearts, the paradigm for godly living is different. No longer is the law’s presence in our hearts dependent on our efforts to put it there. True, it still helps to read, study, and memorize the Bible. But Jesus’ presence in our hearts does something that reading and studying the Bible can’t do (Rom. 8:3). Jesus’ presence in us perfectly aligns our new hearts with the will of God for man (Rom. 8:4). Jesus’ presence permanently and completely incorporates God’s laws into our new hearts (2 Cor. 3:3).
Having God’s laws written upon our hearts means that everything God wants and expects of man is fulfilled in us (Rom. 8:4). God wants us to love Him with all our hearts (Mark 12:30). With Jesus in our hearts, that is exactly what we do [explained here]. God wants us to love our neighbors as ourselves (Luke 10:27). With Jesus in our hearts, that is exactly what we do [explained here]. God wants us to love our fellow Christians (John 15:12). With Jesus in our hearts, that is exactly what we do [explained here]. God calls us blessed if we hunger and thirst for righteousness. With Jesus in our hearts, that is exactly what we do [explained here].
These things (and everything else God wants and expects of us) have become part of who we are in Christ. They are ours, not because we found them in the Bible and hid them in our hearts, but because God brought them with Him when He came to live in us. God desired men’s hearts to be right with Him, and He made it so by giving us His Spirit. Everything He wanted to be in us—love for Him, love for the world, and love for our brethren—He has put in us in the person of Jesus Christ. God built these things into our Divine NAture, our spiritual DNA, and these things will never change.
This does not mean, of course, that we are the beneficiaries of sinless perfection. On the contrary, our sinful flesh still exists and is just as sinful after our salvation as before. But what it does mean is that we have new life in Christ Jesus. We have separate new divine natures that are completely in line with God. With Jesus at the core of our being inside our new hearts, our new hearts produce all the godly hopes and desires that God has ever wanted man to have. With Jesus in our hearts, we possess everything we need for life and godliness. Now, to overcome the flesh and its lusts for evil, we must day by day, moment-by-moment, look to Jesus as He shows us how to live out the very things He has put in us. And we don’t need to worry about condemnation if we fail—because all our sins are forgiven.