Reformed theology is often associated with “covenant theology.” If you listen carefully, you’ll often hear pastors and teachers describe themselves as “Reformed and covenantal.” The terms Reformed and covenant are used together so widely that it behooves us to understand why they are connected.

Covenant theology refers to one of the basic beliefs that Calvinists have held about the Bible. All Protestants who have remained faithful to their heritage affirm sola Scriptura, the belief that the Bible is our supreme and unquestionable authority. Covenant theology, however, distinguishes the Reformed view of Scripture from other Protestant outlooks by emphasizing that divine covenants unify the teachings of the entire Bible.

Earlier developments in the Reformed, covenantal understanding of Scripture reached a high point in seventeenth-century England with the Westminster Confession of Faith (1646), the Savoy Declaration (1658), the London Baptist Confession of 1689, and each representing different groups of English-speaking Calvinists. With only slight variations among them, these documents each devote an entire chapter to the way God’s covenants with humanity reveal the unity of all that the Bible teaches.

For example, the Westminster Confession of Faith speaks of God condescending to reveal Himself to humanity by means of covenant. It then divides the entire history of the Bible into just two covenants: the “covenant of works” in Adam and the “covenant of grace” in Christ. The covenant of works was God’s arrangement with Adam and Eve before their fall into sin. The covenant of grace governed the rest of the Bible. In this view, all stages of the covenant of grace were the same in substance. They differed only as God administered His one covenant of grace in Christ in various ways throughout biblical history.

Along these same lines, a number of more recent Reformed theologians have affirmed the covenantal unity of Scripture by relating particular biblical covenants to what the New Testament calls “the kingdom of God.” Jesus indicated the importance of God’s kingdom in the opening words of the Lord’s Prayer: “Our Father in heaven, hallowed be your name. Your kingdom come, your will be done on earth as it is in heaven” (Matt. 6:9–10). Jesus’ words first indicate that the foremost goal of history is the glory and honor of God Himself. Yet, His words also indicate that God will receive this glory through the coming of His kingdom to earth as it is in heaven. God’s goal has always been to receive the eternal praise of every creature by establishing His glorious kingdom on earth. To borrow from the well-known praise of Revelation 11:15, at the end of history “the kingdom of the world [will] become the kingdom of our Lord and of His Christ, and he shall reign forever and ever.”

Recent archaeological discoveries have shown how God’s covenants related to His earthly kingdom. In the days of the Bible, many kings of nations surrounding Israel administered the expansion of their kingdoms through international treaties. Biblical scholars have noticed remarkable parallels between these ancient treaties and the biblical covenants with Adam, Noah, Abraham, Moses, David, and Christ. These similarities indicate that the Scriptures present covenants as God’s way of administrating the expansion of His kingdom on earth.

Biblical covenants emphasized what was needed at specific stages of God’s kingdom by furthering the principles of previous covenants. God started with Adam to reveal His own kingship, the role of humanity, and the destiny He had planned for the earth (Gen. 1–3). These principles were then carried forward as God promised stability in nature for humanity’s service in Noah’s covenant (Gen. 6, 9). God enhanced His previous covenants by promising that Abraham’s descendants would become a great empire and spread God’s blessings to all other nations (Gen. 15, 17). God built on these covenants by blessing Israel with His law in the days of Moses (Ex. 19–24). Every previous covenant was taken to new heights as God established David’s dynasty and promised that one of his sons would rule in righteousness over Israel and over the entire world (Pss. 72; 89; 132). All Old Testament covenants were then furthered and fulfilled in Christ (Jer. 31:31; 2Cor. 1:19–20). As the great son of David, His life, death, resurrection, ascension, and return eternally secure the transformation of the entire earth into God’s glorious kingdom.

Many evangelical Christians today find it difficult to believe that everything in Scripture after Genesis 3:15 concerns God’s kingdom administered through the unfolding of one covenant of grace. The majority of American evangelicals view Scripture as divided into periods of time governed by substantially different theological principles. When Christians follow this popular approach to Scripture, it is not long before they become convinced that the new covenant of our day is actually at odds with many aspects of the Old Testament.

At least three issues often move to the foreground: works and grace, corporate and individual faith, and earthly and spiritual concerns. First, many evangelicals believe that the Old Testament’s emphasis on good works is incompatible with salvation by grace through faith in Christ. Second, Israel’s corporate relationship with God as a community appears to have been replaced by a focus on the individuals’ personal relationships with God. Third, many evangelicals believe that the Old Testament call to establish an earthly kingdom for God stands in contrast with the New Testament emphasis on a spiritual kingdom in Christ.

Covenant theology has enabled Reformed theologians to see that the New Testament is actually quite similar to the Old Testament in these three areas. First, in this view salvation by grace through faith in Christ was the only way of salvation in both Testaments. The entire Bible calls for good works because saving faith always yields the fruit of obedience to God. Second, covenant theology helps us see that both Testaments speak about individual and corporate relationships with God. All of God’s covenants deal with people on both levels. Third, covenant theolog y has shown that God’s kingdom has always been earthly and spiritual. The Old and New Testaments focus on our service in both realms. In these and other ways, covenant theology has much to offer the broader evangelical community.

At the same time, there is also a growing need for covenant theology to be strongly reaffirmed in contemporary Reformed circles. In recent decades, many newer advocates of Reformed theology have neglected covenant theology.

More and more, we find that Reformed theology has been reduced to what we often call the doctrines of grace — familiar beliefs such as total depravity, unconditional election, limited atonement, irresistible grace, and perseverance of the saints. Of course, we should value these truths of Scripture, but when we fail to stress the larger framework that covenant theology provides, our understanding of the Bible soon begins to suffer in the same three areas.

First, the doctrines of grace without covenant theology have led some to believe that Reformed theology is primarily concerned to teach that God’s grace sustains the Christian life from beginning to end. Of course, this is certainly true. Yet, the covenants of both testaments consistently teach that God has always required determined effort from His people in response to His grace and that He will reward obedience and punish disobedience.

Second, apart from covenant theology, many people in our circles seem to think that our theology is all about finding uniquely Reformed ways for individuals to improve their relationships with God. In our day, a number of paths toward personal holiness and devotion have been treated as the central features of Reformed theology. As important as individuals are in the Bible, covenant theology highlights our corporate relationship with God as well. No biblical covenant was made with just one person. They also involved God establishing relationships with groups of people. For this reason, both testaments teach us that the families of believers are covenant communities within which God’s mercy is passed from one generation to another. Moreover, the visible church in both testaments is the covenant community within which we receive the gospel and the ordinary means of grace.

Third, the doctrines of grace easily give us the impression that Reformed theology is only concerned with spiritual matters. Many people in our circles are deeply concerned with inward transformation by a true understanding of Scripture. Yet, we often neglect the physical and social effects of sin and salvation. Covenant theology gives us a far larger and more compelling vision of our hopes as Christians. In both testaments, believers extend God’s kingdom both to spiritual and earthly realms. We are to teach the gospel of Christ to all nations so that people may be transformed spiritually, but this spiritual renewal is for the sake of extending the lordship of Christ to every facet of culture around the world.

All of this is to say that covenant theology has much to offer every Christian. So when we ask ourselves, “What is Reformed theology?” it will serve us well to respond, “Reformed theology is covenant theology.”