At Reformed Forum we often speak about the organic unity of the Scriptures. This is the basic idea that the Old Testament is naturally related to the New Testament. I’m using “naturally” in distinction from “artificially.” In the Old Testament God is revealing his plan and purpose to his people of old, but he’s revealing it to them in “seed” form.
Just as soon as Adam and Eve sin in Genesis 3, God promises to provide the seed of the woman who would crush the head of the serpent. He promises them a redeemer, no one other than Jesus Christ.
There in Genesis 3 we see Christ, but he is revealed in shadowy form—as a seed compared to a full flowering plant. God’s full plan of redemption in Jesus Christ has not fully unfolded. Later on, we see it in greater detail as God reveals himself to Abraham, Isaac, and Jacob. We see it through Moses and the Mosaic Covenant through David and the Theocratic Kingdom. In all of these stages, we come to see more and more the greatness and the fullness of our Lord and Savior Jesus Christ so that when Jesus Christ comes in the flesh and he accomplishes his perfect work of redemption. He is fulfilling that which was depicted and revealed in advance throughout the Old Testament.
Just as a seed is planted and then watered it comes to sprout from the ground. Over time it grows and matures into a larger plant. We then begin to see it bud and eventually it will blossom into a full flower. All the beauty and grandeur we see in that process over time is part of a whole. No phase is discreet and unrelated to the whole. The parts are naturally—as opposed to artificially—related to one another. What we see in the growth of that plant over time is the unfolding of what it is intended to be from the very beginning.
Likewise, when we read of the Apostles speaking about Christ as the fulfillment of the Old Testament, they are underscoring that Christ is the sum and substance of Old Testament revelation. The Apostles are not artificially placing Christ onto the Old Testament Scriptures as if they’re somehow engaging in some form of reader response theory. Jesus is not tacked onto the message of the Old. The Scriptures from beginning to end are all about Jesus Christ. He is the sum and substance of the word of God. He is the word of God incarnate and all of his word is organically related.