One God, Two Testaments

Like me, many of you reading this article did not grow up in a church that is part of the Reformed tradition. You did not have the benefit of being catechized in the Westminster Standards or the Heidelberg Catechism. Calvinism may have been a dirty word, if not in your home, then in your church. You have come to embrace the doctrines of grace after years of personal study because you have been unable to deny the truth of divine election, which is found throughout Scripture.

My journey into the Reformed tradition followed this path, but it was not only the doctrines of grace that led me to sit under John Calvin, the Westminster Divines, B.B. Warfield, R.C. Sproul, and others as theological mentors. In fact, I often think that the Holy Spirit used my interest in the Old Testament more than anything else to help me see and accept the biblical truths summarized in Reformed theology.

When I speak of the Spirit’s use of the Old Testament, I am not referring to the plain descriptions of divine providence, election, and so on found therein. The Old Testament does teach the doctrines of grace, but this is not what attracted me to Reformed theology in the first place. Instead, the Reformed tradition’s comprehensive appreciation for the Old Testament and its understanding of the continuity between the old and new covenants is what drew me in. Many of the teachers and authority figures I had while growing up had a tendency to frown upon the old covenant Scriptures. There was no direct disparaging of the Old Testament; nevertheless, this part of the Bible was often thought to be in conflict with the New Testament. No serious attempt was ever made to explain how the Old Testament is to guide the life of the believer today. To make matters worse, when I had a question about a specific old covenant text, I was told not to worry about it, because “those passages in the Old Testament are not for the church.”

These attitudes and approaches were not satisfying to me because I knew that the Law and Prophets are God’s Word to His people even today. Reformed theology attracted me because out of all of the competing Christian traditions it does the best job of summarizing the New Testament’s teaching on the Old Testament. Through distinguishing between law and gospel, I found that Reformed theologians do not separate the two, understanding that both law and gospel are present in every book of the Bible. The penetrating insight into the Ten Commandments in Reformed documents like the Westminster Confession of Faith showed me how Calvinists understand that the Law is not some afterthought or something easily relegated to a bygone era. God’s eternal precepts are found within the old covenant commandments, and I was thrilled to see that Reformed theologians are willing to do the hard work to search out these principles and apply them to us today. No other theological system addresses these topics with such devotion, comprehensiveness, and biblical fidelity.

Even so, Reformed theology has not answered all my questions about the old covenant. I am still puzzled at times about the continuity and discontinuity between the new covenant and the old. This puts me in good company, since most teachers struggle with such things as well. How is the old covenant binding upon us today? Do we emphasize the similarities of the old and new covenants or their differences? 

We will likely be asking these questions until the Lord returns. Until then, it seems wisest to err on the side of continuity and maintain the old covenant practices not specifically repealed in the New Testament. Reformed theology takes this approach, especially in its understanding of issues like Sabbath observance and infant baptism, which practices depend largely on an appeal to covenant continuity.

Despite my desire to smooth out the distinctions between the old covenant and the new, I know that I can never escape the discontinuity between these administrations. I also realize that believers can legitimately disagree regarding covenant continuity and therefore on the nonessentials that depend so much on it. Still, we can find common ground. We may disagree, for example, on what Jesus would have us do on the Sabbath today, but we can all agree that we can never again look at this day apart from Christ. Considered in this light, we can focus on how the Sabbath points ultimately to its Lord, Jesus Christ (Matt. 12:1–8), and less on lists of dos and don’ts.

As we approach the Bible, we must always remember that the same God gave us both Testaments, and so we cannot separate fully the old covenant Scriptures from the new. Yet we must always consider each text through the lens of Christ, for it is impossible to consider any text, or anything else, apart from Him.