Think about that one for a minute.
Something tells me that we ought to have a good answer for a question as apparently simple as that, and yet something tells me that most of us do not. Or, maybe this is a better way to ask it: What was wrong with the Old one? If it ain’t broke, don’t fix it, right? So, what was “broke” in the Old one that needed fixing in the New?
In Jeremiah 31:31-34, the Lord makes the following promise to the people concerning the coming New Covenant: “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. But 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.”
This is the key text in the Old Testament for understanding the nature of the New Covenant, and the author of Hebrews does us the benefit of giving us an authoritative, divinely-inspired exposition of the Jeremiah passage in Hebrews 8. In v. 7, he writes, “For if the first covenant had been faultless, there would have been no occasion [i.e. ‘necessity’] to look for a second.” In other words, there was something wrong with the Old Covenant. Or better, there was something deficient in it. There was something that did not suffice. So the question remains: What was deficient? What was ‘broken’? Why was there a need for another covenant that replaced the Old and superseded it by virtue of its being “enacted on better promises” (8:6)? What are the “better promises” of the New Covenant?
Hebrews explains: “For he finds fault with them when he says, ‘Behold, the days are coming, declares the Lord, when I will establish a new covenant…not like the covenant that I made with their fathers…. For they did not continue in my covenant, and so I showed no concern for them, declares the Lord'” (8:8-9).
This, then, was the essential fault and failure of the Old Covenant: the people within the covenant could disobey and fall out of the covenant. The Old Covenant contained no ‘staying power.’ It provided no guarantee of persevering obedience. No guarantee that God would exert his power to keep his people in the covenant.
Andrew Murray, the great Dutch pastor and missionary of the 19th century explains: “Israel began well, and accepted the covenant, and promised obedience. But they continued not [to be faithful]. There was no power to continue; no power to conquer temptation or the evil heart; to remain faithful. Against this, the New Covenant would provide [power to continue], because it was better, enacted on better promises. It would, by the blood of Christ, provide such an actual putting away and cleansing of sin that God would actually remember [their sin] no more forever. With this He would, by His Holy Spirit, so put His laws into their heart that they would delight in doing them. God would Himself work both to will and to do [good in believers]” (The Holiest of All, 288).
In sum: the Old Covenant was deficient in that it bore no truly good news. It said to the sinner, in essence: “Be faithful and endure if you can, for if you do God will give you life and blessing. If you cannot remain faithful and endure, the curses of breaking covenant with God will come upon you.” This is not good news because no one remains faithful. No one can endure in and of themselves. “There is none righteous, no not one” (Rom. 3:10).
That’s why the New Covenant is good news. This is the essence of the “better promises”: God not only promises life and blessing for obedience and endurance, but he also promises to provide obedience and endurance to the end for his elect. The Old Covenant was deficient because the people of God could fall out of it! The New Covenant is good news because God will ensure that his people will not fall out of it. New Covenant believers are a people “who by God’s power are being guarded through faith for a [final!] salvation ready to be revealed in the last time” (1 Pet. 1:5).
The Arminian view of perseverance, that God will not prevent believers from breaking covenant with him if they so choose, destroys the good news and better promises of the New Covenant.