The Relationship Between the Covenants


The Old Testament’s relationship to the New Testament, and the implications its law has for Christian living today are important and sometimes controversial subjects that have profound impacts on how Christians understand their identity in Christ. Unfortunately, we sometimes fail to properly explore these issues and simply default to whatever answer is most convenient for us in any given situation. So, we want to take some time to explore this relationship to find out how God’s old covenant relates to his new covenant, and how God’s children are meant to understand the law of his old covenant in light of his new promises in Christ.

Ferguson illustrates a point that may be useful to this pursuit in how the Jews translated their Hebrew word of “covenant” into the Greek:

When the Jews translated their Bible into Greek, they faced the problem of how to express the Hebrew word for “covenant”: berith. One possibility was synthēkē, which expressed the idea of mutuality, a compact or treaty. This word preserved one aspect of the Hebrew covenant, an agreement, but did not do justice to the predominant emphasis on God’s initiative, so the translators chose diathēkē, a word meaning “disposition” or “arrangement.” In view of the Hebrew background, the emphasis was on the dispensation of God. The common Hellenistic usage of diathēkē was for a testament or last will. This was a particular kind of disposition and provides the imagery for Galatians 3:15 and Hebrews 9:17.8 Otherwise, the New Testament uses “covenant” according to the Jewish background, in every case keeping the emphasis on the divine disposition, a laying down, whether of promises or of conditions.

Ferguson, E. (1996). The church of Christ: a biblical ecclesiology for today (p. 8). Grand Rapids, MI: Wm. B. Eerdmans Pub. Co.

The Jews understood that God’s promises were not so much “arrangements between equals” as they were the promises of God’s divine disposition and will. God’s children receive an “inheritance”, not a “payout”. Our identity as God’s children is inextricably rooted in his sworn promises made to Abraham and David. For example, the opening verses of the New Testament begins with “Jesus the Messiah, the son of David, the son of Abraham” (Mt. 1:1). Peter draws on the Old Testament to declare that the resurrected Christ now occupies the throne of David (Acts 2:30-32; cf Ps. 16:10; 132:11; 2nd Sam. 7:12-13). Paul also understands the everlasting covenant of kingship with king David as being promised to the resurrected Christ (Acts 13:32-35; cf Psalm 2:7; 16:10; Is. 55:3). God’s mission to bring the Gentiles into his covenant relationship is taken from Amos’ prophecy that God will raise up David’s fallen dynasty so that “they may possess… all the nations that are called by my name” (Acts 15:16-17; Amos 9:11-12).

We will benefit if we explore some of the covenant-language employed by the New Testament that draws its meaning from the Old Testament so that we can properly understand the relationship that exists between the Old and New Testaments.

First, Jesus identifies the cup during the last supper with his “blood of the covenant, which is poured out for many for the forgiveness of sins” (Matt. 26:28; Mark 14:24; Luke 22:20; cf. 1 Cor. 11:25). The foundation for this new covenant was found in the old covenant, wherein God promised to forgive their new sins on the basis of his faithful love (Jer. 31:33-34). Jeremiah’s prophecy of the new covenant dominates how the writer of Hebrews understands Christ’s sacrificial death, blood, and priesthood (Heb. 7:22; 8:6-12; 9:15-23; 12:24; cf. 2 Cor. 3:6). Likewise, the ministry of the high priest functions as both a template for the sin-offering require to atone for sins and as an illustration of the weakness in the old covenant (Leviticus 16:14-16 cf Heb. 8:7-8; 10:1-4; Rom. 8:3). Thus, where the old covenant never provided an adequate basis for the once-and-for-all forgiveness of sins (Heb. 9:12-15; 10:4), in Christ God has made provision for the total forgiveness of sins so that our relationship with God might be established and sustained in the grace of Christ (Heb. 8:8-13). Whereas the sacrifices of the Mosaic law gave them access to God’s forgiveness up to the time of the sacrifice, Christ’s death covers the totality of all sins so that no new sacrifice is required. The new covenant is sealed with the blood of Christ that makes eternal atonement (Heb. 9:12), so it is an “eternal covenant” (Heb. 13:20). Once again, we see what God has done in Christ illuminating the proper human response.

Again, Ferguson concisely illustrates an important relationship between the Old and New covenants:

Ephesians 2:11-17 contrasts the previous condition of Gentiles with their status in Christ. The Gentiles formerly were “strangers to the covenants of promise” (vs. 12). The Mosaic law provided a wall of separation between Jews and Gentiles. “Commandments and ordinances” (vs. 15) is the language for the Old Testament laws. Jesus has abolished this law that separated Jews and Gentiles (vs. 15) in order to bring them together as one new people.

The fullest use in the New Testament of the theme of the new covenant is found in Hebrews. The book reiterates some of the points found above in Paul and adds its own distinctive thrust. One of these new motifs is the priesthood of Christ. He did not qualify as a priest under the Mosaic law (Heb. 7:14), so the author argues that he belongs to a different order of priests, that of Melchizedek (Heb. 7:1-28). A consequence of the change in priesthood is that the law has been changed (Heb. 7:12). To accept the priesthood of Christ requires one to acknowledge a change in the law as well. The earlier commandment was abrogated (Heb. 7:18) so that there might be introduced a better hope (Heb. 7:19); “accordingly Jesus has also become the guarantee of a better covenant” (Heb. 7:22). The faults the writer of Hebrews finds with the old arrangement were that the priests kept on dying (Heb. 7:23) and had to keep on making atonement for their own sins (Heb. 7:27). In contrast, the covenant basis is now new, for the sacrificer (Heb. 7:15-17) and the sacrifice (Heb. 7:25; 9:25-27) are forever.

Ferguson, E. (1996). The church of Christ: a biblical ecclesiology for today (pp. 13–14). Grand Rapids, MI: Wm. B. Eerdmans Pub. Co.

The basis for gentile inclusion into the covenant of Christ’s blood is the change in priesthood by which the new covenant is administered. Without the Old, the New would not be possible.

Jesus mediates a better covenant based on new promises (Heb. 8:6), causing the old covenant to pass away (Heb. 8:13) because the first covenant was made weak through human flesh (Heb. 8:7-8; 10:1-10; cf Rom. 8:3). As the old covenant was fulfilled and gave way to the new covenant, so too all of its institutions likewise became obsolete (i.e. the priesthood, sacrifices, and sanctuary). The first covenant that was a shadow and copy of things to come (Heb. 10:1-4) gave way to the promises of God that would bring about true righteousness (Heb. 10:9).

Again, Ferguson succinctly notes:

The replacement of the institutions of old Israel through Christ’s once-for-all action did not, however, remove for the writer of Hebrews the authority of the message of the Old Testament, for he bases his whole argument on it.

Ferguson, E. (1996). The church of Christ: a biblical ecclesiology for today (p. 14). Grand Rapids, MI: Wm. B. Eerdmans Pub. Co.

The Old Testament is not discarded as useless by the coming of the New Testament, rather, it now functions to uphold the New Testament, serving as the foundation upon which the blood of Christ’s covenant now stands. The Old Testament is the word of God, not because it prescribes how his children are meant to respond and relate to him in Christ, but because it upholds our identity in Christ and informs how we understand what God has done in Christ!

Finally, the new covenant brings the promised Holy Spirit, who now writes the law of God on our hearts (2 Cor. 3:2, 6, 8; Gal. 3:14 cf Jer. 31:33-34; Ezk. 36:26-27). The reality of what God has done in Christ is now imprinted upon our very souls!

In all of this, God’s new promises draw on his old in order to fulfill them and accomplish his wise plan of redemption in the new covenant of Christ’s blood. We see the relationship between the Old and the New as one working through the other, by which the Old upholds and advances the New. The Old is not discarded as irrelevant or useless, but in the proper time when the Old had accomplished all that it needed to accomplish, it gave way to the New so that all of God’s promises might be “yes” and “amen” in Christ!


God’s covenant is the basis for his relationship with people, it establishes what that relationship will look like, and how he acts towards them. Therefore, God’s covenant defines how he relates to people. On the other hand, God’s law illuminates how people are supposed to respond to him. When God declares his promises, he also often makes clear how we should respond to those promises. To Abraham, he commanded that he “go to the land that I will show you” (Gen. 12:1). To Moses, he commanded that Israel “keep the Lord’s commands and statutes” (Deut. 10:13; 27:1).

This is easy enough to understand, but when God makes new promises, what are we meant to do with the old laws that once governed how God’s people were supposed to respond to his promises?

Ferguson makes some useful observations about the practical relationship between God’s law and his promises:

The promise to Abraham is not abrogated by the law given to Moses (Gal. 3:17). The promises made to Abraham and his descendants apply to Christ, who is the true offspring (seed) of Abraham (Gal. 3:16). Everyone who is in Christ and who belongs to Christ shares Christ’s status, so what is said of Christ in Galatians 3:16 is said of the church in 3:29: “If you belong to Christ, then you are Abraham’s offspring, heirs according to the promise” (Gal. 3:29). Those who have been baptized into Christ have put on Christ (Gal. 3:27) and become one people in him (Gal. 3:28), the spiritual children of Abraham (Gal. 3:29). God accounts as his people all who are in Christ in fulfillment of the promise to Abraham. This is all a matter of promise, without reference to merit.

Ferguson, E. (1996). The church of Christ: a biblical ecclesiology for today (p. 10). Grand Rapids, MI: Wm. B. Eerdmans Pub. Co.

God’s sworn promises to Abraham came before the laws that were given to Moses, therefore, his covenant promises always precede and supersede the laws. According to God’s faithful love, we share in Christ, who is the fulfillment of God’s sworn promises to Abraham, which were given nearly 400 years before the Sinai covenant and laws. But we must not conclude from this that the law is now useless; Jesus did not come to abolish the law that was given by Moses, but to abundantly fulfill every righteous demand by the blood of his new covenant (Mt. 5:17-20; cf. Rom. 8:3-4). Therefore, we have received new promises in Christ through what God promised to Abraham long ago and Christ’s blood satisfied the demands that were made through Moses’ law.


More is needed on this topic because of the unique role that the Sinai Covenant played in redemptive history. Although it is useful to show that Moses’ laws governed a different covenant from the one that Christians receive, to simply say that Abraham’s promises came before Moses’ laws is insufficient to explain why Christians are not bound by Moses’ laws.

Ferguson again makes an important observation about the Sinai Covenant:

Unlike the note of continuity sounded by the New Testament about the Abrahamic and Davidic covenants, the Sinai covenant is placed in contrast to the “new covenant” in Christ Jesus. Many passages affirm that Christians, or at least Gentile Christians, are not under the Mosaic covenant as the basis of their relationship with God and, therefore, are not bound by its ceremonial and ritual stipulations. There is a new covenant based on a new means of forgiveness and of appropriation of that forgiveness. Romans 7:1-7 contrasts “the old written code” of the Mosaic law with “the new life of the Spirit” (vs. 6). In order to show the temporary validity of the law of Moses, Paul compares the marital relationship. A “married woman is bound by the law to her husband as long as he lives,” but the death of the husband breaks that bond (vss. 2-3). Changing the point of reference but maintaining the principle that death discharges a person from the obligation to a law, Paul proceeds to declare that the one who has died to the law through the body of Christ can be married to Christ (vs. 4), and presumably only someone who has so died to the law can be. “Now we are discharged from the law” (vs. 6). Verse 7’s reference to the last of the Ten Commandments makes clear that it is the law of Moses that Paul has been discussing.

Ferguson, E. (1996). The church of Christ: a biblical ecclesiology for today (pp. 11–12). Grand Rapids, MI: Wm. B. Eerdmans Pub. Co.

We are joined with Christ in baptism into his death, burial, and resurrection (Rom. 6:1-6) so that in Christ we died to the law through his body so that we could belong to him who was raised from the dead and bear fruit for God (Rom. 7:4). Therefore, if we are joined to Christ, the old person who once was bound to answer to the laws of Moses (see 1 Tim. 1:9-11) is now crucified, and just as spouses are no longer bound after death, we are made new in Christ (2 Cor. 5:17) in order that we might now belong to him as his holy bride (2 Cor. 11:2).

The Law of Moses is carefully contrasted with the ministry of the Holy Spirit. Paul shows that the response that was once dictated from tablets of stone now inwardly arises from the heart of the new person (2 Cor. 3:3). He shows that what was once weak because of our human flesh, is now accomplished through the powerful ministry of the Holy Spirit (2 Cor. 3:6). Because of our human weakness, Moses’ law held people captive under the ministry of condemnation, but through the power of the Spirit, the new covenant sets us free by the ministry of justification (2 Cor. 3:7-9), revealing the surpassing glory of what is done by God in Christ Jesus (2 Cor. 3:10-11). Likewise, the difference is not only in the covenant, but also in its recipients: those who once read the old covenant with a veil could not see the glory of the Lord (2 Cor. 3:12-18) but now we may see with unveiled faces because we have turned to the Lord (2 Cor. 3:16).

The Sinai covenant is the basis for the blood of Christ’s covenant (Ex. 12:3, 11-13; Lev. 1:4-5; 4:6-7; 17:11); God’s covenant with Moses made room for what Christ did on the cross to atone for our sins, and by atoning for our sins, we might die to the law so that we could forever live to God! Paul, therefore, acknowledges the glory of the Sinai Covenant (2 Cor. 3:10) and uses that glory to illustrate the surpassing glory of what God has done in Christ (2 Cor. 3:4, 11).

Though I risk dragging this point out too much, we should also briefly survey Paul’s letter to the churches in Galatia, wherein he argued that gentiles were free from the requirements of the “works of the law” on the basis of what Christ had accomplished on the cross (Gal. 3:23-25). In other words, the Sinai Covenant has ushered us into the reality of adoption in Christ, wherein we are all now son’s and daughter’s of God! We inhabit a new reality. Our relationship with God has taken on new definition. We have a new identity in Christ.

Paul employs the analogy of children at length to emphatically illustrate the difference between the two covenants: “Sarah” and “Hagar” both represent two covenants (Gal. 4:24), with “Hagar” representing the Sinai Covenant “bearing children of slavery” and “Sarah” representing the “Jerusalem from above”, whose children are free (Gal. 4:25-26). In the same way that Isaac was born according to God’s promise, so are we now children of promise born of the Spirit (Ga. 4:28-29). The law illuminated those who lived according to the flesh, that is, those who were born by natural means into the old covenant. Now, the Spirit illuminates those who live according to the Spirit, who are born not of natural means (Jn. 1:13), but of the Spirit. Therefore, Paul uses Sarah’s words to Abraham as a spiritual template for God’s children being set free by the covenant of Christ’s blood (Gal. 4:27; cf Gen. 21:10).

Therefore, in the same way that the Laws of Moses followed God’s deliverance from the land of Egypt, so now there must also be a new law illuminating the proper human response to God’s faithful promises by which we have been delivered from the power of sin and death. God’s children respond and relate to him by faith working through love (Gal. 5:6). We live in divine freedom for the purpose of love (Gal. 5:13), which abundantly fulfills all righteousness (Gal. 5:14). God’s children live their lives in this world in the Holy Spirit (Gal. 5:16) as those who are free from the law (Gal. 5:18) because they have died to the law (Gal. 2:19; cf Rom. 7:4) and become new creations (Gal. 6:15).


When we consider the identity of the Christian Church and the expressions of her testimony in this world, we should not neglect the promises of God from which the new covenant of Christ’s blood draws its meaning. We should take time to understand how the Old Testament provides the foundation upon which the New Testament stands; how God’s purpose in the Old provided the means to bring about the New. And we should not forget that we could not have the law of the Spirit written on our hearts without the law of Moses that was written on tablets of stone!

Therefore, while the remainder of this series will focus primarily on drawing out the identity, purpose, and structure of the Christian Church from the New Testament, we will do so in light of the foundation upon which the New Testament stands.

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