With whom was the covenant of grace made?
The covenant of grace was made with Christ as the second Adam, and in him with all the elect as his seed.1
Scripture proofs
The Westminster Assembly's proof texts (KJV). The bracketed numbers in the answer above mark the clause each set of references supports; expand a row to read the verses.
1 Gal. 3:16; Rom. 5:15–21; Isa. 53:10–11
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.
Rom. 5:15 But not as the offence, so also is the free gift. For if through the offence of one many be dead, much more the grace of God, and the gift by grace, which is by one man, Jesus Christ, hath abounded unto many.
Rom. 5:16 And not as it was by one that sinned, so is the gift: for the judgment was by one to condemnation, but the free gift is of many offences unto justification.
Rom. 5:17 For if by one man’s offence death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ.)
Rom. 5:18 Therefore as by the offence of one judgment came upon all men to condemnation; even so by the righteousness of one the free gift came upon all men unto justification of life.
Rom. 5:19 For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous.
Rom. 5:20 Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound:
Rom. 5:21 That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord.
Isa. 53:10 Yet it pleased the LORD to bruise him; he hath put him to grief: when thou shalt make his soul an offering for sin, he shall see his seed, he shall prolong his days, and the pleasure of the LORD shall prosper in his hand.
Isa. 53:11 He shall see of the travail of his soul, and shall be satisfied: by his knowledge shall my righteous servant justify many; for he shall bear their iniquities.
This doctrine across the Standards
Where the Confession and the Westminster Shorter Catechism treat the same matter, so the question can be studied alongside its parallel statements.
In the Westminster Confession
VII.3 Man by his fall having made himself incapable of life by that covenant, the Lord was pleased to …
Man by his fall having made himself incapable of life by that covenant, the Lord was pleased to make a second, commonly called the covenant of grace: wherein he freely offered 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.
→ VII.3 · Of God's Covenant with ManVII.4 This covenant of grace is frequently set forth in the Scripture by the name of a testament, in …
This covenant of grace is frequently set forth in the Scripture by the name of a testament, in reference to the death of Jesus Christ the testator, and to the everlasting inheritance, with all things belonging to it, therein bequeathed.
→ VII.4 · Of God's Covenant with ManVII.5 This covenant was differently administered in the time of the law and in the time of the gospel: …
This covenant was differently administered in the time of the law and in the time of the gospel: under the law it was administered by promises, prophecies, sacrifices, circumcision, the paschal lamb, and other types and ordinances delivered to the people of the Jews, all fore-signifying Christ to come, which were for that time sufficient and efficacious, through the operation of the Spirit, to instruct and build up the elect in faith in the promised Messiah, by whom they had full remission of sins and eternal salvation; and is called the Old Testament.
→ VII.5 · Of God's Covenant with ManVII.6 Under the gospel, when Christ the substance was exhibited, the ordinances in which this covenant is dispensed are …
Under the gospel, when Christ the substance was exhibited, the ordinances in which this covenant is dispensed are the preaching of the Word and the administration of the sacraments of Baptism and the Lord's Supper; which, though fewer in number, and administered with more simplicity and less outward glory, yet in them it is held forth in more fulness, evidence, and spiritual efficacy, to all nations, both Jews and Gentiles; and is called the New Testament. There are not, therefore, two covenants of grace differing in substance, but one and the same under various dispensations.
→ VII.6 · Of God's Covenant with ManXVII.2 This perseverance of the saints depends, not upon their own free will, but upon the immutability of the …
This perseverance of the saints depends, not upon their own free will, but upon the immutability of the decree of election, flowing from the free and unchangeable love of God the Father; upon the efficacy of the merit and intercession of Jesus Christ; the abiding of the Spirit and of the seed of God within them; and the nature of the covenant of grace: from all which ariseth also the certainty and infallibility thereof.
→ XVII.2 · Of the Perseverance of the SaintsXXVII.1 Sacraments are holy signs and seals of the covenant of grace, immediately instituted by God, to represent Christ …
Sacraments are holy signs and seals of the covenant of grace, immediately instituted by God, to represent Christ and his benefits, and to confirm our interest in him: as also to put a visible difference between those that belong unto the Church and the rest of the world; and solemnly to engage them to the service of God in Christ, according to his Word.
→ XXVII.1 · Of the SacramentsXXVIII.1 Baptism is a sacrament of the New Testament, ordained by Jesus Christ, not only for the solemn admission …
Baptism is a sacrament of the New Testament, ordained by Jesus Christ, not only for the solemn admission of the party baptized into the visible Church, but also to be unto him a sign and seal of the covenant of grace, of his ingrafting into Christ, of regeneration, of remission of sins, and of his giving up unto God, through Jesus Christ, to walk in newness of life: which sacrament is, by Christ's own appointment, to be continued in his Church until the end of the world.
→ XXVIII.1 · Of BaptismVIII.1 It pleased God, in his eternal purpose, to choose and ordain the Lord Jesus, his only-begotten Son, to …
It pleased God, in his eternal purpose, to choose and ordain the Lord Jesus, his only-begotten Son, to be the Mediator between God and man, the Prophet, Priest, and King; the Head and Saviour of his Church, the Heir of all things, and Judge of the world; unto whom he did, from all eternity, give a people to be his seed, and to be by him in time redeemed, called, justified, sanctified, and glorified.
→ VIII.1 · Of Christ the MediatorIn the Westminster Shorter Catechism
Q.20 Did God leave all mankind to perish in the estate of sin and misery?
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.
→ Open Q.20