At first view there appears to be some confusion in the statements of the Scriptures as to the parties to this covenant. Sometimes Christ is presented as one of the parties; at others He is represented not as a party, but as the mediator and surety of the covenant; while the parties are represented to be God and his people. As the old covenant was made between God and the Hebrews, and Moses acted as mediator, so the new covenant is commonly represented in the Bible as formed between God and his people, Christ acting as mediator. He is, therefore, called the mediator of a better covenant founded on better promises.
Some theologians propose to reconcile these modes of representation by saying that as the covenant of works was formed with Adam as the representative of his race, and therefore in him with all mankind descending from him by ordinary generation; so the covenant of grace was formed with Christ as the head and Representative of his people, and in Him with all those given to Him by the Father. This simplifies the matter, and agrees with the parallel which the Apostle traces between Adam and Christ in Rom 5.12-21, and 1 Cor. 15.21, 22, 47-49. Still it does not remove the incongruity of Christ’s being represented as at once a party and a mediator of the same covenant There are in fact two covenants relating to the salvation of fallen man, the one between God and Christ, the other between God and his people. These covenants differ not only in their parties, but also in their promises and conditions. Both are so clearly presented in the Bible that they should not be confounded. The latter, the covenant of grace, is founded on the former, the covenant of redemption. Of the one Christ is the mediator and surety; of the other He is one of the contracting parties.
This is a matter which concerns only perspicuity of statement. There is no doctrinal difference between those who prefer the one statement and those who prefer the other; between those who comprise all the facts of Scripture relating to the subject under one covenant between God and Christ as the representative of his people, and those who distribute them under two. The Westminster standards seem to adopt sometimes the one and sometimes the other mode of representation. In the Confession of Faith Chap. 7 section 3) it is said, ‘Man, by his fall, having made himself incapable of life by that covenant [by the covenant of works], the Lord was pleased to make a second, commonly called the covenant of grace; wherein He freely offereth unto sinners life and salvation by Jesus Christ, requiring of them faith in Him, that they may be saved, and promising to give unto all those that are ordained unto life, his Holy Spirit, to make them willing and able to believe.’ Here the implication is that God and his people are the parties; for in a covenant the promises are made to one of the parties, and here it is said that life and salvation are promised to sinners, and that faith is demanded of them. The same view is presented in the Shorter Catechism, according to the natural interpretation of the answer to the twentieth question. It is there said, ‘God having out of his mere good pleasure, from all eternity, elected some to everlasting life, did enter into a covenant of grace, to deliver them out of the estate of sin and misery, and to bring them into an estate of salvation by a Redeemer. In the Larger Catechism, however, the other view is expressly adopted. In the answer to the question, ‘With whom was the covenant of grace made ? ‘ it is said, ‘ The covenant of grace was made with Christ as the second Adam, and in Him with all the elect as his seed’ ‘ (Q. 31).
Two Covenants to be Distinguished
This confusion is avoided by distinguishing between the covenant of redemption between the Father and the Son, and the covenant of grace between God and his people. The latter supposes the former, and is founded upon it. The two, however, ought not to be confounded, as both are clearly revealed in Scripture, and moreover they differ as to the parties, as to the promises, and as to the conditions.