By Dr. J Ligon Duncan
Much of the confusion that I see in the current theological discourse within the various Reformed branches of the Reformational churches pertains to an ignorance of historic covenant theology. By historic or classical covenant theology, I mean the bi-covenantal theology exhibited in, for instance, the Westminster Confession of Faith (but with a pedigree stretching back to Zurich and Geneva, and behind them on into the Patristic era) which fully appreciates the fundamental difference between God's dealings with man pre- and post-Fall, and thus the vital distinction between God's goodness and his grace. C.H. Spurgeon was right when he asserted: "The doctrine of the covenant lies at the root of all true theology. It has been said that he who well understand s the distinction between the covenant of works and the covenant of grace, is a master of divinity. I am persuaded that most of the mistakes which men make concerning the doctrines of Scripture, are based upon fundamental errors with regard to the covenant of law and of grace."
The current popularity of sundry mono-covenantal approaches (that is, systems that deny the covenant of works/covenant of grace framework of biblical history, whether they are Barthian or Hoeksemanian or Schilderian) exists only because of a widespread lack of familiarity with the more robust historic Reformed tradition on this subject. Furthermore, a serious effort at historical theological reacquaintance with classical bi-covenantal Reformed theology would also prove to be a great boon to current Reformed-Lutheran dialogue on the relation of their law-grace hermeneutic to the Reformed covenant of works-covenant of grace hermeneutic of Pauline polemics.
Covenant theology is the Gospel set in the context of God's eternal plan of communion with his people, and its historical outworking in the covenants of works and grace (as well as in the various progressive stages of the covenant of grace). It explains the meaning of the death of Christ in light of the fullness of the biblical teaching on the divine covenants, undergirds our understanding of the nature and use of the sacraments, and provides the fullest possible explanation of the grounds of our assurance. Put another way, covenant theology is the Bible's way of explaining and deepening our understanding of: (1) the atonement [the meaning of the death of Christ]; (2) assurance [the basis of our confidence of communion with God and enjoyment of his promises]; (3) the sacraments [signs and seals of God's covenant promises—what they are and how they work]; and (4) the continuity of redemptive history [the unified plan of God's salvation]. Covenant theology is also an hermeneutic, an approach to understanding the Scripture—an approach that attempts to biblically explain the unity of biblical revelation.
Covenant theology is a blending of biblical and systematic theology. It is biblical theology in the sense that covenant theology recognizes that the Bible itself structures the progress of redemptive history through the succession of covenants. It is systematic theology in that it recognizes the covenants as a fundamental architectonic or organizing principle for the Bible's theology. Thus it proceeds to integrate the biblical teaching about the federal headships of Adam and Christ, the covenantal nature of the incarnation and atonement, the continuities and discontinuities in the progress of redemptive history, the relation of the Jewish and Christian scriptures, law and gospel, into a coherent theological system.
Covenant theology is not a response to dispensationalism. It existed long before the rudiments of classical dispensationalism were brought together in the nineteenth century. Covenant theology is not sectarian, but an ecumenical Reformed approach to understanding the Bible, developed in the wake of the magisterial Reformation, but with roots stretching back to the earliest days of catholic Christianity and historically appreciated in all the various branches of the Reformed community (Baptist, Congregationalist, Presbyterian, Anglican, and Reformed). In light of this, J.I. Packer is surely right when he says "in modern Christendom covenant theology has been unjustly forgotten" (see his introduction to Witsius' Economy of the Covenants (P&R).