The heart of the human problem is the problem of the human heart. If the heart is the problem, then a change of heart is necessary.
Mere external show of religion won’t do. That’s the problem of Judah during the time of the prophet Jeremiah. God is “near in their mouth [but] far from their heart” (Jer. 12:2). Because that’s the problem, God commanded them to “circumcise…your hearts” (4:4) and “wash your heart from evil, that you may be saved” (4:14). If the heart remains unchanged, they will continue their departure from God toward certain destruction.
God commanded them to change their hearts. But can they do it? How about you? Can you do it? Can you perform a heart surgery for your own heart? They need to change their hearts, but they cannot do that, we cannot do that. It is beyond our power. “The sin of Judah is written with a pen of iron; with a point of diamond it is engraved on the tablet of their heart, and on the horns of their altars” (17:1). “Can the Ethiopian change his skin or the leopard his spots? Then also you can do good who are accustomed to do evil” (13:23).
A heart solution, then, is humanly impossible. We can’t, but God can do that for us. And God promises to do that for us. God promises a new covenant in Jeremiah 31:31-34. This is one of the most crucial passages in the Old Testament. We need to study this so that we may understand the heart of the human problem and the divine solution this problem requires.
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 neighbor 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.