In Scripture, God’s covenantal work always is attached to that blessed refrain: “I shall be your God, and you shall be My people.” In and through the covenant of grace, God is His people’s, and His people are His own. It is, therefore, through attention to covenant theology that we are best able to know our God and to live as His people.
Throughout Scripture, certain phrases are repeated often, and their repetition signals their importance. One such recurring phrase is called the “Immanuel Principle,” wherein God declares, “I shall be your God, and you shall be My people” (e.g., see Gen. 17:7; Ex. 6:7; Jer. 31:1; Ezek. 36:28; 2 Cor. 6:16; Rev. 21:3). These words speak of the most precious of relationships—the relationship by which God’s people belong to Him as His own. Scripture elaborates to tell us that God has created, and is creating, this relationship through covenant. As God tells the children of Israel in Deuteronomy 29:12–13, He has gathered them together “so that [they] may enter into the sworn covenant of the Lord [their] God, . . . that he may establish [them] as his people, and that he may be [their] God.” By and through covenant, God is making His people His own, and He is showing Himself to be their God. Since covenant is such an important biblical category, it demands the careful attention of God’s people.
What is Covenant Theology?
When considering the category of covenant, an obvious question emerges: What is a covenant? In Scripture, a covenant is a binding relationship among parties that involves both blessings and obligations (e.g., Josh. 9:3–21). In many ways, marriage is a good example of a covenant relationship. Marriage is a relationship to which both parties are solemnly committed, and that relationship brings both blessings and obligations to husband and to wife. Stated differently, a covenant is a relationship within parameters.
If a covenant is a relationship within parameters, what is covenant theology? Covenant theology seeks to use the biblically prominent covenants to inform our knowledge of God and of His work. Specifically, covenant theology contends that God has been working throughout history to gather His people to Himself through covenantal relationship.
The Covenant of Works
The first covenantal relationship one encounters in the Scriptures is the covenant of works, which is the relationship in the garden of Eden between God and Adam as the representative or head of all mankind. This relationship between God and Adam is a rich one. God has made humanity—both man and woman—in His own image (Gen. 1:26–27), He has breathed life itself into Adam (Gen. 2:7), He has placed His image bearers in a garden overflowing with abundant provision for all their needs (Gen. 1:29–30; 2:8–9), and in that place of blessing, man enjoys immediate communion with God Himself (Gen. 3:8). Even more, God has given Adam commands that instruct him how he is to live as God’s image bearer. Under these creation ordinances, man is commanded to exercise dominion over the earth (Gen. 1:28; 2:19), to labor (Gen. 2:15), to marry (Gen. 2:24–25), to fill the earth (Gen. 1:28), and to enjoy doxological rest on the Sabbath day (Gen. 2:3). Adam and Eve are God’s image bearers, living in God’s paradise, in fellowship with their Creator, and with instructions on how to reflect the glory of God Himself. Nestled amid these blessings, God also has commanded Adam that he is not to eat of one tree in the garden—the Tree of Knowledge of Good and Evil. If Adam eats of that tree, he will die (Gen. 2:16–17). But if Adam lives out a life of “perfect and personal obedience” (Westminster Confession of Faith 7.2), he will attain everlasting life. In His condescending love for His image bearers, God is holding out a way that finite man can inherit everlasting life in His presence. By covenant, God would gather humanity fully to Himself.
An Eternal Covenant of Grace
Adam, of course, failed to uphold that covenant. In an act of flagrant rebellion, Adam ate of the fruit of the forbidden tree and brought the covenantal curse of death not only upon himself but also upon all the posterity whom he had represented in the covenant (Rom. 5:12–14; 1 Cor. 15:22). In the shambles of Adam’s rebellion, however, God declared a promise. Despite Adam and Eve’s rebellion, God would preserve a people to Himself, from generation to generation, and ultimately, from that people, God would raise up One who would destroy the enemy of the souls of His people (Gen. 3:15). This was the promise of a Messiah and of a people who belonged to Him. It was God’s announcement not of the covenant of works but of His covenant of grace.
In the New Testament, the Scriptures provide more precise clarity on this covenant of grace. When God promised redemption in Genesis 3:15, He was not beginning something new. From eternity, there had been an intra-Trinitarian agreement, sometimes referred to as the covenant of redemption, in which the Father had covenanted to give a people to the Son (Luke 22:29; John 17:12), the Son had covenanted to serve as the Mediator of this people and do everything required to bring them into perfect fellowship with God (John 17:4; 19:30; Heb. 1:3), and the Holy Spirit had covenanted to apply the work of the Son to the people whom He had been given by the Father (John 16:7–11; Acts 2:33; 2 Cor. 1:21–22). When God promised restoration in the ruins of Eden, He was announcing the glories that were to come from that eternal covenant.
As God’s eternal purpose, announced in Genesis 3:15, came to historical accomplishment in the covenant of grace, it precisely addressed the need of God’s people. Because of Adam’s sin, all mankind bore a double burden. First, they stood under the curse of the covenant of works. Because of Adam’s transgression, all mankind justly deserved death. But this burden, as grim as it was, was not their only burden. As the covenant of works had shown, for man to live eternally in God’s presence, he had to have a positive, righteous obedience. He had to keep the law of God. Both the curse and the terms of the covenant of works stood between fallen mankind and life in God’s presence. As the Mediator of God’s people in the covenant of grace, God the Son would satisfy both of those demands. In His own death, the Son would suffer the curse of the covenant of works in His people’s place (Gal. 3:13). And in His perfect keeping of God’s law, He would fulfill the terms of the covenant of works in their stead (Rom. 5:18; 2 Cor. 5:21). Through the working of this eternal covenant of grace, the triune God would redeem His people and bring them to Himself.
The Covenant of Grace Unfolds
As God brought this eternal covenant to fulfillment in time, He did so through a succession of covenants, often referred to as historical administrations of the covenant of grace. In these historical administrations, as God was moving His redemptive purposes forward, He also was progressively revealing more about how He was redeeming His people and about how He would have them to live as a people who were His, holy as He is holy (Ezek. 37:24–28; Gal. 3:15–22; Lev. 19:2; 1 Peter 1:15–16). After first announcing His eternal covenant of grace in Genesis 3:15, God entered into such historical administrations of that covenant with Noah (Gen. 6–9), with Abraham (Gen. 12; 15; 17), with Israel at Mount Sinai (Ex. 19–24), and with David (2 Sam. 7:1–17) before realizing, in Christ, the new covenant that He previously had foretold through the prophets (Jer. 31:31–34; Matt. 26:26–28; Luke 22:20).
Initially, after God’s promise in Genesis 3:15, it appeared to the human eye that the gradual unfolding of God’s covenantal purpose would fail before it even began. Beginning with jealousy and murder among Adam and Eve’s children (Gen. 4:1–8), humanity spiraled into ever-deepening sin until their wickedness had produced a world that heralded man’s obscene evil rather than God’s covenantal glory (Gen. 6:5–7).