This book is designed to be an accessible introduction the covenant theology that stands in the heritage of seventeenth-century Baptist covenant theologians. Renihan introduces the book by laying four foundations for Baptist covenant theology. First, he claims that covenant theology covers all of Scripture and yet must avoid “facile reductions or generalizations” (13). Instead, it “must be built on supporting premises, and the supporting premises must be studied as completely and thoroughly as possible” (13).
Second, Renihan distinguishes between creation and covenant and between natural law and positive law. God is not naturally obligated to give man any reward for obedience. That arrangement is not natural but covenantal. Likewise, covenants go beyond natural law, which is “the universal moral law of God” (15) and introduces positive law, “indifferent things prescribed or proscribed for a particular period, place, and people” (15). Thus, an interpreter cannot infer from the presence of a particular feature in one covenant that such features must be present in all covenants. Different covenants can have different positive laws.
Third, Renihan distinguishes between two ways of thinking about law and gospel. Law and gospel can be thought of as “two opposite paths of righteousness” (20). They can also be thought of as “two historical time periods, the Old and New Testaments” (20). It is important to note that law and gospel in the first sense are present in both these periods. This accounts for covenant continuity. But the historical sense should prevent covenant theologians from identifying “the Abrahamic, Mosaic, and Davidic covenants with the new covenant, or covenant of grace” (22).
Fourth, the Pauline concept of mystery indicates that there was partial revelation that awaited fuller explication in the New Testament. Thus, “a covenant theology’s treatment of the Old Testament must preserve the presence of Christ as a mystery. And one’s covenantal system must not so flatten out the progress of redemptive history that it effectively, even if unintentionally, unveils the mystery before its actual unveiling” (24).