As has already been pointed out in this issue, “Reformed” theology just is “covenant” theology. However, that doesn’t necessarily settle the question as to what kind of covenant theology is being espoused. By far the question that has been taken up the most in the history of Reformed theology is whether the covenant that Israel made with God at Sinai is a re-publication or renewal of the covenant of works made with humanity in Adam. Agreeing on the covenant of works/covenant of grace scheme, Reformed pastors and theologians nevertheless differed over the question of the Mosaic covenant. Was Israel, like Adam, expected to fulfill a covenant of works and at least remain in the land on the basis of its own obedience?
Answering that question with a “yes,” many of the great Reformed thinkers of the past (such as Rollock, Perkins, Owen, Witsius, all the way to Charles Hodge) carefully pointed out that the promises made to the nation of Israel were of two types: temporal and conditional on one hand, and everlasting and unconditional on the other. In Genesis 15, God unilaterally swears to Abraham that He will give to his descendants a land and that He will bless the whole world through his seed. Yet at Mount Sinai, the people swear an oath to keep God’s law (“All this we will do”), and this is the condition not for entering God’s typological land of rest (since that was already a gift) but for remaining in the land and securing God’s blessing (“that you may live long in the land the Lord your God is giving you”). On this interpretation, the land-promise is conditional. The entire theocracy that God commands as part of this covenant at Sinai is provisional — to use the language of the New Testament (Hebrews), “a shadow of things to come.” It was never intended to bring salvation but only to serve as a type of the salvation that the Lord Himself would bring. Walking in Adam’s shoes, Israel also proves unfaithful. “Like Adam, they transgressed the covenant” (Hos. 6:7).
All of this bad news sets us up for the good news in Jeremiah 31:31–34. Crucial especially in Jeremiah’s announcement is the fact that this new covenant will not be like the Sinai covenant, which Israel broke. Even in Deuteronomy, we are confronted with the impossible demand to circumcise our own hearts, to fulfill God’s commands, and to preserve ourselves and our families in the land. However, Israel’s history proves what we already knew about humanity in Adam: Even with God’s commands written on tablets, we are transgressors. Even Israel is “in Adam,” under a curse, unable to bring about that obedience that God’s good law requires. The new covenant, like the promise to Adam after the fall, renewed in the covenants with Abraham and David, is not like the Sinai covenant. The blessings of the new covenant do not depend on our obedience, but on God’s grace: He will put His Law within us, so that it will not only be an external command that condemns us but an inward longing of our heart; He will be our God and we will be His people — yet another one-sided promise on God’s part. Instead of always giving imperatives (like “Know the Lord”), in the new covenant people will know the Lord because He has revealed Himself as their Savior. In fact, the basis for all of this is clear in verse 34: “For I will forgive their iniquity, and I will remember their sin no more.” Forgiveness is the basis for everything else. Once God completely clears their debt, the heirs of this new covenant will be given the new hearts and a new relationship to God that could never be accomplished under the Law.
The Law is good, but we are not. The Law commands, but cannot give. It tells us what must be done, but helping us get it done is simply not in the Law’s job description. It condemns us for violation, but cannot exercise clemency for violators.
But once the Law’s legitimate claim against us is satisfied, the gospel and the law conspire together to give us both grace and direction for our Christian life, in relation to God and our neighbors. Having fulfilled the Law as well as having borne its wrath in our place, “canceling the record of debt that stood against us with its legal demands” by “nailing it to the cross” (Col. 2:14), we who were dead in sins are now made alive. Baptized into Christ’s death and resurrection, we now “put on” the “new self” (Col. 3:1–17). As Jeremiah 31 made so clear already, the new covenant is effective because it rests on indicatives, not imperatives; on gospel, not law; on promises, not commands. Notice that I didn’t say the new covenant dispenses with imperatives, laws, or commands, but merely that it is not based on them. God has done in Christ what the Law could not do in us. In Christ, God not only finds the perfect substitute for our sins but the fulfiller of all righteousness on our behalf. We are not only forgiven, but are accounted as those who have perfectly fulfilled God’s moral will in thought, word, and deed.
In this way, the classic covenant theology that is promoted by Reformed theology shares Paul’s concern simultaneously to uphold the Law and yet demonstrate that this can only be done if there is a way for us to be forgiven, justified, renewed, and sanctified on the basis of another’s Law-keeping. Because of Christ’s success as the second Adam and faithful Israel, we can enter God’s rest — this time, not the typological rest, in Canaan, but the everlasting rest to which it pointed and for which Abraham, Isaac, Jacob, Moses, and David all longed. Once the new covenant arrived in the person of Christ, the old covenant became obsolete (Heb. 8:13). Having served its function of leading Israel to Christ, the sacred status once applied to the nation and its land is now applied to the body of Christ, consisting of Jewish and Gentile believers together. This church constitutes “a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light” (1 Peter 2:9).
What then are we to say about Moses’ status in the church today? Reformed theology has traditionally insisted that the moral law (that is, the Ten Commandments) remains in force, while the ceremonial and civil laws of the old covenant are now obsolete along with that covenant itself. No other nation was brought into a covenant relation with God as a typological witness to His coming kingdom. While the Sinai covenant is itself a covenant of works, where Israel promises to do everything it says on pain of death, we inherit God’s promises in a covenant of grace. And precisely because Christ has fulfilled the covenant of works for us, we can inherit all of the everlasting promises in a covenant of grace. Only the heirs of that covenant, after all, are able to begin in this life to say with the Psalmist, “How I love your law, O Lord!”