Rev. Key is pastor of the Protestant Reformed Church of Randolph, Wisconsin.

As we continue our study of the doctrine of Christ, we have yet to consider Christ’s specific relationship to the covenant of God. Three passages in the epistle to the Hebrews underscore the significance of that relationship. All three speak of Christ as the Mediator of the covenant. They are Hebrews 8:6, Hebrews 9:15, and Hebrews 12:24.

In Hebrews 8:8-10 we read, “For finding fault with them, he saith, Behold, the days come, saith the Lord, when I will make a new covenant with the house of Israel and with the house of Judah: Not according to the covenant that I made with their fathers in the day when I took them by the hand to lead them out of the land of Egypt; because they continued not in my covenant, and I regarded them not, saith the Lord. For this is the covenant that I will make with the house of Israel in those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people.”

The subject of this particular section of Hebrews is the covenant of God, and particularly the superiority of the new covenant over the old covenant. So in Hebrews 8:6 Christ is called “the mediator of a better covenant, which was established upon better promises.”

In Hebrews 9 the same theme is continued and developed, all the focus being on Christ as the fulfillment of the Old Testament sacrifices and priesthood. “And for this cause he is the mediator of the new testament (covenant, sk), that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance” (Heb. 9:15).

Apparently the translators of the King James Version were looking ahead to the next three verses when they translated the word “covenant” as “testament.” For Scripture points out here that, from one important point of view, the covenant is similar to our legal testaments or wills.

It is a mistake to equate the covenant with a legal agreement or contract, as it is often defined. Essentially the covenant is very different from a legal testament or will. But there is one aspect of the covenant that bears the characteristic of a testament, and that is that a testament goes into effect only upon the death of the testator. That is, though I may already have prepared a will for my wife and children, that will goes into effect only after I die. It is that particular matter to which the inspired writer calls our attention in pointing to the fulfillment of God’s covenant. The new covenant goes into effect only by the death of Him who has established that covenant.

Christ is the Mediator of the new covenant.

We must attempt to grasp the significance of that truth. We must know our Savior as the Mediator of the new covenant. We must know His salvation not merely as a pardon of our sins, but as bringing God’s covenant with us to realization. And therefore we must know ourselves as God’s covenant people in Christ.

The Covenant

Let us review briefly the concept of the covenant. We also have to take note of the idea of the old versus the new covenant.

In the first place, the book of Hebrews makes clear, as does all of Scripture, that God is a covenant God. His dealings with His people are covenant dealings. The salvation that He gives is a covenant salvation.

The writer to the Hebrews reminds God’s people of the essential meaning and significance of the new covenant when he writes in Hebrews 8:10, with reference to that covenant, “I will be to them a God, and they shall be to me a people.” The covenant is that relationship in which God is God to His people, and the people of His covenant are His people.

To put it another way, the covenant is that relationship of love and fellowship which God establishes and realizes with His people in Christ, and in which He gives us to enjoy the intimacy of His own covenant life as the triune God.

Scripture points us to the truth that this covenant relationship between God and His people is pictured in Christian marriage. In marriage a special relationship is established, the primary characteristic of which is fellowship, the fellowship of love. When God reveals Himself to us in Christ Jesus, He establishes with us a relationship in which we enjoy the fellowship and love of His own life, and we in turn love Him as our God and Redeemer.

The Old and New

We face a question, however, in that Hebrews refers to the old covenant and the new covenant. Does this not point to two different covenants? And how, if there is an old covenant and a new covenant, is it possible to speak of the covenant as a relationship of love and fellowship? Isn’t the idea of a contract or legal agreement much more fitting to the idea of an old and a new covenant?

It would appear, from a cursory reading of Hebrews 8 and 9, that there are two different covenants being referred to, and that the first was set aside for some reason and replaced by the second. Is it, perhaps, that the old covenant is the covenant of the law, and the new covenant is the covenant of the gospel? Was the old a covenant of works, while the new is a covenant of grace?

But it is exactly this error of making separation between the Old and New Testaments and speaking of two essentially different covenants that has led to several other serious theological errors.

In fact, the failure to understand these passages of Scripture has contributed to the development of dispensationalism in its various forms. It has led to the idea that we must look for a future special work of God with the Old Testament nation of Israel. There are multitudes in this country and around the world who believe that the promise made in the old covenant was an earthly promise to the Jews which must yet find fulfillment in the earthly land of Canaan.

That error is especially striking given the testimony of Scripture that Abraham himself knew better than to look for the fulfillment of the promise in the earthly land of Canaan. For we read in Hebrews 11 that Abraham “looked for a city which hath foundations, whose builder and maker is God.” And so that there might be no doubt that Hebrews 11:10 speaks of the heavenly Canaan, we read in verse 16, “But now they desire a better country, that is, an heavenly: wherefore God is not ashamed to be called their God: for he hath prepared for them a city.”

The same failure to understand this distinction that is made between the old and new covenant has also contributed in no small part to the denial of infant baptism. For if the covenant of God in the New Testament age is now essentially different from that in the Old Testament, then certainly the sign of the covenant, besides having a different form, will also have a different meaning and application.

So our understanding of “old” and “new” covenant is critically important.

In answer to those questions about the reference to old and new, we must understand that Scripture teaches only one, everlasting covenant. It is the covenant of grace.

That covenant was established with the one people of God, the true, spiritual children of Abraham. Galatians 3 summarizes the teaching of the entire Old Testament on this point. “Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ” (Gal. 3:16).

To Christ was the promise given. In Christ was the covenant established. All the focus comes together in Him.

What about Abraham’s other children? The apostle goes on to explain in Galatians 3:29: “And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise.”

The new covenant is new not merely by virtue of being more recent, not just because it follows the old covenant. But it is new in that it is the real thing! The covenant is now realized in its highest, most beautiful form — that is, on this side of heaven. For God has become flesh, to dwell among us, to take us into the fellowship of His own life! The tabernacle of God is with men!

Jesus Christ has become the Mediator of the covenant!

Christ as the Mediator of the Covenant

How extremely important is this work of Christ as Mediator of the covenant! He is the One who alone can bring about the covenant fellowship between God and His people. He is the One who alone is able to realize the blessings of the covenant, and make them ours. Without Him as Mediator there can be no covenant of God with men.

Any fellowship of friendship and love between the majestic and perfectly holy God and fallen and depraved men is absolutely impossible without a Mediator — without God’s Mediator, Jesus Christ. The reason is clearly expressed by Isaiah in Isaiah 59:2, when he tells the church, “Your iniquities have separated between you and your God, and your sins have hid his face from you, that he will not hear.”

When two have become estranged to this degree, there can be no reconciliation, there can be no fellowship, there can be no peace, apart from the work of a mediator.

Christ is the Mediator of the covenant. He is so by appointment of God. He is so as a wonder of God’s sovereign grace.

The covenant is indeed a covenant of grace.

God appointed Christ as Mediator of the covenant. We had nothing to do with that, nothing at all.

God sent Christ in the incarnation as Mediator of the covenant. We had nothing to do with that, nothing at all.

And as the Mediator Christ has reconciled us to God and realized that everlasting covenant of grace with us, in which we now stand and are called the sons of God, His friends.

In order to accomplish that work, Christ had to die. Hebrews 9:15 emphasizes that amazing work of Christ our Mediator. “And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.”

Jesus Christ sealed the covenant with his own blood. He satisfied God’s justice in our place and on our behalf. He delivered us from the curse of the law, that law that was so prominent under the old covenant. That belonged to His work as Mediator, Mediator of the covenant, Mediator between God and His elect people.

And upon this particular, redemptive sacrifice as Mediator of the covenant depends all Christ’s work as Mediator today.

The exalted Christ still works as Mediator of the covenant today. On God’s behalf He is teaching us as our Prophet; He is interceding for us as our only High Priest; and as King He is ruling us by His Word and Spirit.

Through Him and Him alone we enjoy the riches of God’s fellowship, the life of His love.

All that awaits us is the perfection.

It surely awaits us, because of Christ, the Mediator of the covenant.