It had been a long couple of days for Jesus. The day before (or perhaps the day before that), Jesus had fed 5,000 men—not including women and children—who ended up leaving enough food to fill 12 baskets. Because of such a miracle the people were ready to take him by force and make Him king. Thankfully, Jesus was able to get away, and also send the Twelve away before they were unduly influenced by mob-rule. The disciples had waited for Jesus, but Jesus was up on a mountain praying. He had been praying for so long that His disciples decided to leave Him and take off to the other side of the Sea of Galilee (as they had been commanded earlier). Of course, this is when Jesus walked upon the water out to the boat in the midst of the storm, landing the boat at its destination. From there he went throughout the region healing people. The people even brought their sick, dying, and unclean into the marketplace in hopes of touching the hem Jesus’s garment. Being God, His power would not be depleted, but being man, surely, He was tired. His disciples would be exhausted having fought a storm all night long. It would be understandable if they simply forgot to wash their hands before eating. Who would not forgo the washing of hands when one is tired and hungry? Apparently, the Pharisees and scribes. “For the Pharisees and all the Jews do not eat unless they wash their hands properly, holding to the tradition of the elders,” (Mark 7:3, ESV). Incredulous, they accused the disciples and Jesus of defiling themselves by eating without washing their hands. Most likely, they had touched open wounds, the lame, blind, and perhaps even lepers. The unclean had been touched and now they were eating without washing their hands. This action was unacceptable. It is not hard to imagine the indignation. After all, who does not tell their child to go wash their hands after playing in the dirt? That’s not even a religious or ceremonial rite. Jesus, however had not forgotten to wash His hands; he simply did not need to. Jesus called the Pharisees and scribes out on their putting the traditions above the law, but to the disciples he gave a deeper explanation:
Do you not see that whatever goes into a person from outside cannot defile him. . . What comes out of a person is what defiles him. For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery, coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. All these evil things come from within, and they defile a person, (Mark 7:18b, 20-23, ESV).
What defiles the person is what is already inside the person. What Jeremiah said in 17:9 is true: “The heart is deceitful above all things, and desperately sick; who can understand it,” (ESV)? As John Owen wrote, “The heart of man is known only by God. We do not know the hearts of others. We do not even know the secret intrigues and schemes, twists and turns, actions and tendencies of our own hearts. All but the infinite, all-seeing God are utterly ignorant of these things.”
Since sin resides in the recesses and crevasses of the heart, that which is outside the heart is powerless to affect a change within the heart. This includes the law of God. Because of sin’s residency within the heart, the outward law of God simply enflamed what was already present. Like the troops storming the Branch Davidian Compound in Waco, Texas, so the law storms the heart. Just as the Branch Davidians showed what was already known—namely they were filled with various types of firearms and much ammunition—so the heart shows what is already known—it is filled with all manner of evil, as Jesus pointed out. “The very commandment that promised life proved death to me. For sin, seizing an opportunity through the commandment, deceived me and through it killed me,” (Romans 7:10-11, ESV).
From the beginning this was known. Though it is possible that Israel had committed idolatry while in Egypt, one does not find this in the Pentateuch. It is only after the Sinaitic Covenant had been agreed to by the people of Israel, including the commandment forbidding the making of graven images, that the people of Israel demanded a golden calf be made. It is no coincidence that when Moses recounted the story to the children of those who made the golden image—having reminded them of his carving new tablets and receiving the law once again—that he tells them they are to obey it, but first, “Circumcise therefore the foreskin of your heart, and be no longer stubborn,” (Deut. 10:16, ESV). The issue was the heart all along. Moses knew that and God knows that. The law was given that all who receive it would know that. Yet, because of the deception of the heart, it is impossible for a person to be honest enough to see the sin that dwells within. That means that no one can actually circumcise their own hearts; God must do it for them.
In speaking with those who were about to enter the Promised Land, Moses told them that they would be disobedient and there would be consequences for that disobedience. Death, famine, war, exile, and more would come upon the people. Yet, God did not leave them without hope. Eventually, in God’s time-table, the heart would be circumcised. “And the LORD your God will circumcise your heart and the heart of your offspring, so that you will love the LORD your God with all your heart and with all your soul, that you may live,” (Deut. 30:6, ESV). God would eventually do what the Sinaitic Covenant was powerless to do. “For God has done what the law, weakened by the flesh, could not do,” (Romans 8:3a, ESV).
How would He eventually circumcise the heart? By means of a new covenant. While in the exile prophesied by Moses in Deuteronomy 29, Jeremiah speaks of this new covenant reality.
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, (Jer. 31:31-34, ESV).
The question is, however: is this a completely new covenant, separated from the Sinaitic Covenant, or is this a covenant renewed and/or remastered? The answer lies in whom you ask. L. C. Allen would claim that this is a brand new covenant. “The proclamation [of Jeremiah 31:31-34] draws a formal contrast between the old covenant and its human breakdown, on the one hand, and its new counterpart and divine undergirding, on the other hand.” C. F. Keil concurs: “The covenant which the Lord will make with all Israel in the future is called a ‘new covenant,’ as compared with that made with the fathers at Sinai, when the people were led out of Egypt; this latter is thus implicitly called the ‘old covenant.’” However, Calvin would disagree with these scholars.
Now as to the new covenant, it is not so called, because it is contrary to the first covenant; for God is never inconsistent with himself, nor is he unlike himself. He then who once made a covenant with his chosen people, had not changed his purpose, as though he had forgotten his faithfulness. It then follows, that the first covenant was inviolable; besides, he had already made his covenant with Abraham, and the Law was a confirmation of that covenant. As then the Law depended on that covenant which God made with his servant Abraham, it follows that God could never have made a new, that is, a contrary or a different covenant. . . .These things no doubt sufficiently shew that God has never made any other covenant than that which he made formerly with Abraham, and at length confirmed by the hand of Moses.
To Calvin, “new” did not mean different or contrary in its substance, but only in its form. “It being new, no doubt refers to what they call the form; and the form, or manner, regards not words only, but first Christ, then the grace of the Holy Spirit, and the whole external way of teaching. But the substance remains the same. By substance I understand the doctrine; for God in the Gospel brings forward nothing but what the Law contains.”
While Calvin makes a strong case, one cannot deny (not even Calvin) that the writer of Hebrews believes that this is a new covenant in and of itself (cf. Heb 8:13). While there are elements similar to those of the Old Covenant, such as the necessity for a priest and sacrifice, the Old Covenant was a mere shadow of the New. Jesus took on the role of both priest and sacrifice. “But as it is, Christ has obtained a ministry that is as much more excellent than the old as the covenant he mediates is better, since it is enacted on better promises,” (Heb. 8:6, ESV). Christ’s ministry is not a Levitical priesthood, but a priesthood of the line of Melchizedek (cf. Heb 5:6; 6:20; 7:17, 21). This makes Him a greater priest than Aaron and due to a priestly change, a new covenant was to be enacted (cf. Heb. 7:11-12). At the same time, the shadow of the sacrificial system continuously exclaimed that the true substance existed. Just as a tree casts a shadow indicating that a tree exists, so the sacrifices of the Old Covenant cast a shadow indicating that a true sacrifice exists. One simply needs to look up and find the substance rather than looking down and only seeing the shadow.
This New Covenant takes the law, or what one considers the “moral law,” and places it into the heart—the will—of the people. This goes back to the original problem that Moses described in Deuteronomy 10 and Jesus described in Mark 7. The issue is the heart. That which is outside the heart cannot direct the heart. Therefore, the law which was at one time written upon stone tablets would now be written upon the heart where the problem of sin lay. “The law of sin is not a written, commanding law so much as an inbred, impelling, urging law. It proposes in temptation, and because it is inbred, it is strongly compelling. That is why God makes His new covenant internal, implanting it in the heart.” It is the only way to combat that which is inbred, impelling, and urging.
Because this covenant is written upon the heart, it is one that cannot be broken. The law is a part of the will, the heart, the mind. One could not remove the law from the heart any more than one could remove sin from the heart. Because God’s law is there, God is there. Unlike Israel, who had broken the Sinaitic Covenant and had the glory of God depart from their midst, those who partake of the New Covenant have God dwell within them. Though this is not explicit in Jeremiah 31, it is in the New Testament. Jeremiah emphatically stated that God would be their God and they would be His people and, as a result, one would not need to be reminded and taught to obey. In essence, this would no longer be an external religion, but an internal dwelling of God Himself. Hence, one can read Jesus’s words saying, “When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come,” (John 16:13, ESV). Still more, Paul wrote, “We. . .received the Spirit who is from God, that we might understand the things freely given us by God. And we impart this in words not taught by human wisdom but taught by the Spirit, interpreting spiritual truths to those who are spiritual,” (1 Cor. 2:12b-13, ESV). The law is written on the hearts of those in the New Covenant and God Himself, His Spirit becomes a teacher and a guide unto holiness.
This covenant has still even more great news. “For I will forgive their iniquity, and I will remember their sins no more,” (Jer. 31:34d, ESV). Israel and Judah were decimated by their enemies, killed, carried away into exile, or dispersed throughout the known world because their sins were ever before Yahweh. Though they made sacrifices, it was all pretense. Like many who would wantonly sin and then rely upon the confessional to receive absolution, the Israelites would sin without the notion that their sins and confession would be rejected. The sacrifices for their high-handed sins would not be acceptable to Yahweh. For those in the New Covenant, Jeremiah stated that their sin would be forgiven as though it would be a completed act and so they ought no longer worry about whether or not they would receive forgiveness. This God did by way of offering the blood of the New Covenant—the very blood of Christ. “By this offering, Christ has perfected forever the beneficiaries of His sacrifice. The perfection could not come by the law or the Old Testament priesthood. . . Only Christ’s offering was sufficient to bring men near to God. . . and to save them to the uttermost.”
All of this to say: The New Covenant is a brand-new covenant, yet God showed in this covenant the realities of the shadows cast by the Old Covenant. The Old Sinaitic Covenant is obsolete (cf. Heb. 8:13), yet that does not mean that it is useless. As Paul wrote to the Galatians, it is a tutor or guardian (a pedagogue) until Christ came (cf. Gal. 3:24), but it continues to help the New Covenant people understand God’s redemptive plan throughout history, from Creation onward. That is why the shadows causes one to seek the realities.
 John Owen, Triumph Over Temptation: Pursuing a Life of Purity, ed. James M. Houston, (Colorado Springs: Victor Press, 2005), 49.
 L. C. Allen, “Jeremiah, The Book of,” in Dictionary of the Old Testament: Prophets, ed. Mark J. Boda and J. Gordon McConville, (Downers Grove, IL: InterVarsity Press, 2012), 438.
 John Calvin, Calvin’s Commentaries: Volume X, Jeremiah 20-47, (Grand Rapids: Baker Books, 2005), 126-127.
 Ibid., 127.
 Owen, Triumph Over Temptation, 46.
 Homer A. Kent, Jr., The Epistle to the Hebrews, (Winona Lake, IN: BMH Books, 2000), 193.