Covenant theology is the engine that powers the whole system of Reformed doctrine. It is both elegant and complex, providing the framework through which the Reformed read and understand what the scripture says about God’s dealings with man. As we saw last week, every person in history has related to God through the Covenant of Works in Adam or the Covenant of Grace in Christ.
We have a relationship to the Covenant of Works merely by the fact of our existence. Because we are God’s creation, we have a natural duty to keep God’s law. But even beyond that, with Adam as our federal head, we start with not merely a natural relationship to God, but also a covenant relationship through the Covenant of Works. We are covenantally obligated to “do this and live.” Unfortunately, as we know, it is impossible for us to merit eternal life through our own obedience since the fall because Adam’s sin was imputed to us (Rom. 5:12-14).
We know what the problem is, and the solution: we start out having broken our covenant, and we need Christ to mediate for us through the Covenant of Grace. But this brings us to an important question, and a key distinctive of Reformed covenant theology: just who is “in” the Covenant of Grace?
The Church Viewed Two Ways
In Reformed theology, we speak of two categories of relationship to the Covenant of Grace. We have multiple ways of describing these two categories: administration and substance, outward and inward, visible and invisible. The visible church partakes of the outward administration of the covenant, and the invisible church possesses the substance of the covenant–Christ.
The Westminster Confession of Faith describes the invisible church and the visible church in Chapter 25:
I. The catholic or universal Church, which is invisible, consists of the whole number of the elect, that have been, are, or shall be gathered into one, under Christ the Head thereof; and is the spouse, the body, the fullness of Him that fills all in all.
II. The visible Church, which is also catholic or universal under the Gospel (not confined to one nation, as before under the law), consists of all those throughout the world that profess the true religion; and of their children: and is the kingdom of the Lord Jesus Christ, the house and family of God, out of which there is no ordinary possibility of salvation.
Put simply, the relationship between the invisible church and the visible church is one of expression. We interact with and are a part of the invisible church through our relationship to the visible. Berkhof’s description of this relationship is helpful:
The invisible church naturally assumes a visible form. Just as the human soul is adapted to a body and expresses itself through the body, so the invisible Church, consisting, not of mere souls but of human beings having souls and bodies, necessarily assumes a visible form in an external organization through which it expresses itself. The Church becomes visible in Christian profession and conduct, in the ministry of the Word and of the sacraments, and in external organization and government.
Perhaps one of the easiest ways to grasp these two aspects of the church or two ways of relating to the Covenant of Grace is visually. The whole visible church partakes of the administration of the Covenant of Grace, but only the invisible church within possesses the substance. There are both regenerate and unregenerate people within the visible church and both partake of the external administration of the Covenant of Grace–e.g. the assembly of the covenant community for public worship, the ministry of Word and sacrament, church discipline, etc. Since we cannot know who is regenerate, it is impossible for the administration of the covenant to be perfectly congruent with the substance of the covenant.
Back to the Question
So, how do we Reformed answer the question “Who is ‘in’ the Covenant of Grace?” Doesn’t everyone partaking of the Covenant of Grace have Christ as their federal head? The answer again lies in distinguishing in what way we are viewing covenant membership. Are we speaking of substance or administration? Turning again to a diagram, we can see more clearly that election/regeneration are not perfectly congruent with the visible church. We can also see yet a third way of relating to the Covenant of Grace–to be completely outside of it, both in administration and substance. The unregenerate members of the visible church share one thing in common with those outside the covenant: their federal head is Adam. Only those who are part of the invisible church, possessing the substance of the Covenant of Grace, have Christ as their federal head.
So, finally, who is “in” the Covenant of Grace? In the administrative external sense, everyone who participates in the visible church is a covenant member and “in” the Covenant of Grace. In the sense of possessing the substance of the Covenant of Grace, only the regenerate enjoy this inward reality.
For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God. Romans 2:28-29