In his The Holy Trinity, Robert Letham levels a brief criticism against the notion that Christ’s salvation was but a revelation of a covenant made between the Father and the Son and not their very shared nature. Writing against Warfield, Letham states:
By the same token, we point to the obedience of the incarnate Son in the economy of salvation, reflecting his eternal relation to the Father in loving submission, in identity of being and equality of status. The faithfulness of God also undercuts the suggestion made by Warfield—only a suggestion, for he does not pursue it—that certain aspects of the relationship between the Father and the Son in the history of salvation may have been due to a “covenant” between the persons of the Trinity by which the Son submitted himself temporarily to the Father, intending to abandon such submission upon the completion of our salvation. If this were so, the Son could not have revealed God to us.
~The Holy Trinity pg. 401
Barth levels a similar charge against Cocceius. The Covenant of Redemption construct, if allowed to remain an articulation of a new relationship that was somehow added to the natural relation between the Father and Son, does not reveal God to us in salvation.
But what could be clearer than that Jesus Christ is the revelation of God’s fullness? God is love, and the love of God was shown clearly in the giving of His Son to die for the life of the world.
My suggestion is that we follow Murray and others in defining covenant as not a product of the will, but rather as relationship itself. The Covenant of Redemption can be preserved by making it one reflection of the divine fellowship. God’s covenant is simply His own self-revelation finding its fulfillment in Christ. Covenant is God dwelling with man. It is Immanuel.
Jesus Christ is the covenant.