Harry S. Stout, in the preface to The Works of Jonathan Edwards vol. 22, explained that very early in his ministry Edwards began to be driven by a desire to subject theology to the history of the world. This of course culminated in Edwards masterpiece History of the Work of Redemption. As Stout traced the history of Edwards writings and correspondence in regard to this matter he provided a quote from History of the Work of Redemption in which Edwards acknowledges the method of subjecting theology to its historical outworking. What interested me most was the fact that Edwards rooted all of the eternal decree in the covenant of Redemption. Some Reformed theologians will not admit a Covenant of Redemption distinct from the Covenant of Grace. I suggest that such individuals read the following quote in light of their understanding of the eternal aspect of the Covenant of Grace. Edwards wrote:
This work of redemption is so much the greatest of all the works of God, that all other works are to be looked upon as either part of it, or appendages to it, or are some way reducible to it. And so, all the decrees of God do some way or other belong to that eternal covenant of redemption that was between the Father and the Son before the foundation of the world; every decree of God is some way or other reducible to that covenant. And seeing this work of redemption is so great a work, hence we need not wonder that so much is made of it in Scripture, and that ’tis so much insisted on in the histories, and prophecies, and songs of the Bible, for the work of redemption is the great subject of the whole Bible. In its doctrines, its promises, its types, its songs, its histories, and its prophecies.1
While I find this statement attractive on many levels I am not sure that I agree that all the decrees of God are rooted in the Covenant of Redemption. Keep in mind that many theologians speak, not of the decrees of God, but of the decree–since there is no time in the eternal counsel. The Covenant of Redemption itself must have been decreed. So, unless we are willing to say that there was one decree (or one part of the decree) superior to all other decrees (or other parts of the decree), we cannot fully follow Edwards here.The strength of this statement above, as I see it, is the fact that Edwards subjects all revelation to the Covenant of Redemption. That in itself is the grounds of what we now call Biblical Theology. The thing that drove Edwards to conclude that all the decrees of God were rooted in the Covenant of Redemption is the fact that creation served as a stage on which the redemption of men would occur. Anyone who has studied the flood accounts and the Noahic Covenant, will recognize at once how it is that the earth was the sphere in which redemption took place. When God gave Noah the re-creation mandate, He established the Covenant of Grace with him and with every living thing that was in the ark. The rainbow became a sign to God that He would never destroy the earth with a flood as He had done. Why, it should be asked, is this important? Well, God was promising to preserve the sphere in which He would bring about redemption.
The placement of the law against manslaughter also seems to establish this principle. Why would the Lord make a law against shedding blood in this place? One reason seems to be for the preservation of mankind until the redemption of the purchased possession. The restraint of evil would insure the preservation of many.The most important element of Edwards statement is the way in which he includes all parts of Scripture in relation to the Covenant. Rooting it in the eternal counsel of God Edwards says, “And seeing this work of redemption is so great a work, hence we need not wonder that so much is made of it in Scripture, and that ’tis so much insisted on in the histories, and prophecies, and songs of the Bible, for the work of redemption is the great subject of the whole Bible. In its doctrines, its promises, its types, its songs, its histories, and its prophecies.” What stood out most to me was the fact that Edwards referred to the “songs” of the Bible. Since I began working on a covenantal approach to the Song of Songs, I have found no one, in the history of the church, that comes closer to the correct biblico-theological interpretation of the Song than Edwards. It is on account of his subjecting the work of the Redemption, and the redemptive revelation, most consistently to the Covenant of Redemption that he understands that the songs of Scripture are songs of Redemption.
 Works of Jonathan Edwards, 9, A History of the Work of Redemption(New Haven, Yale University Press, 1989) 513-14.