Over the years I've written several posts on the republication of the Covenant of Works at Sinai (i.e. what occurred on Sinai, the Mosaic Covenant) - here, and here, and here - and they have received hits because people are searching and are genuinely confused by this subject because theologians are very confusing in how they write about the subject; and because theologians that believe in infant baptism are very dishonest in how they write about the subject. They're dishonest because they never let on that their main concern in how they formulate Covenant Theology is to protect their doctrine infant baptism. Why are they so panicked to protect that doctrine to the point where they will distort doctrine? Because no matter how often and in how many ways they will deny it they see their salvation resting on the fact that they were ritually water baptized by a cleric. I.e. they believe in baptismal regeneration. We who have experienced regeneration by the word and the Spirit can understand their weakness, but not their refusal to go child-like to the word of God, and to God Himself in prayer (God says several times in his word, move towards Me, and I will move towards you, and this is done by reading his Old and New Testaments with the eyes of a child and by praying to God). They downgrade the fact and reality of supernatural, monergistic regeneration by the word and the Spirit as they downgrade the Bible itself by replacing it with constructed critical text monstrosities that replace the authority of the word of God with the authority of the word of man (scholars, academics, most of them self-identified atheists). Regarding the latter this causes them to look down upon the word of God as if it were merely one of a million text documents created by man and in effect having inherently the inner state of seeing the word of God as something that needs them more that they need it; which, needless to say, is an approach that will keep one in a state of spiritual death.
Having a clear understanding of Covenant Theology is powerful because it is the grand, overarching plan of God, or plan of redemption from one pole of eternity to the other. It presents all the parts of the Bible in a complete, unified whole and enables the believer to see their place within the great journey, or fantasy like novel, that is God's plan of redemption. It enables one to engage confidently in spiritual warfare as a pilgrim on the King's Highway making one's way to the Heavenly Jerusalem. To intentionally teach a version of this Covenant Theology that is distorted and ad hoc merely to protect a desired doctrine (infant baptism) that has no warrant in Scripture to begin with, let alone no warrant to be placed as the central concern in the plan of redemption is purely Satanic. That it's a holdover from Roman Catholicism should not surprise. Remember: the Devil knows what his great enemy is: it's the regeneration of God's elect by the word and the Spirit. Thus the Devil, in the dark days when the Roman Catholic Church had the power of the sword over Christians, called people to be baptized all day and all night, no problem; yet...he kept the word of God away from people upon penalty of torture and death. The Devil knows what regenerates, and it is not ritual water baptism.
It is under this law [the law given to Moses on Sinai] that Christ was born (Gal. 4: 4) and it is this same law (i.e. the covenant of works reaffirmed in the Old Covenant) that Christ fulfilled by his obedience (Rom. 5: 19-20) and it is the curse of this law which he endured by his death (Gal. 3: 13). Christ, therefore, accomplished the Old Covenant perfectly.
Barcellos, Richard. Recovering a Covenantal Heritage: Essays in Baptist Covenant Theology (p. 102). RBAP. Kindle Edition.
The Old Covenant, while being different from the covenant of works, reaffirmed it, not so that Israel would look for life by this means, but so that Christ would accomplish it. The Old Covenant was, therefore, not only necessary to lead to Christ but it was necessary so that he could accomplish salvation for God’s Israel.
Barcellos, Richard. Recovering a Covenantal Heritage: Essays in Baptist Covenant Theology (pp. 102-103). RBAP. Kindle Edition.
Samuel Petto explains this important point:
Indeed, I think, one great end of God in bringing Israel under this Sinai covenant, was to make way for Christ, his being born or made under the law, in order to the fulfilling of it for us. I do not see how (by any visible dispensation) Jesus Christ could have been born actually under the law, if this Sinai covenant had not been made; for the covenant of works with the first Adam being violated, it was at an end as to the promising part; it promised nothing; after once it was broken, it remained in force only as to its threatening part, it menaced death to all the sinful seed of Adam, but admitted no other into it who were without sin, either to perform the righteousness of it, or to answer the penalty; it had nothing to do with an innocent person, after broken, for it was never renewed with man again, as before: therefore, an admitting an innocent person (as Jesus Christ was) into it, must be by some kind of repetition or renewing of it, though with other intendments than at first, viz. that the guilty persons should not fulfil it for themselves, but that another, a surety, should fulfil it for them.[ 227]
Barcellos, Richard. Recovering a Covenantal Heritage: Essays in Baptist Covenant Theology (p. 103). RBAP. Kindle Edition.
This explanation from Petto demonstrates how he himself, and most of the Particular Baptists, considered that the covenant of works was reaffirmed with a different goal than at its first promulgation. The covenant of works did not provide a substitution to satisfy its righteousness; no one could obey in Adam’s place nor suffer his punishment. God, therefore, reaffirmed the covenant of works in another covenant that allowed for a righteous person to substitute himself for sinners. Not only was the Old Covenant not against the promises of God (Gal. 3: 21), but it was given specifically for the accomplishment of these promises (Gal. 3: 22-24). Without being itself a covenant of grace, the Old Covenant was given because of the covenant of grace and with a view to its accomplishment. Is this what the apostle John wanted to underline by declaring: “Out of his fullness we have all received grace in place of grace already given. For the law was given through Moses; grace and truth came through Jesus Christ” (John 1: 16-17)? The law given by Moses was a grace to lead to the grace accomplished by Jesus Christ.
Barcellos, Richard. Recovering a Covenantal Heritage: Essays in Baptist Covenant Theology (p. 103). RBAP. Kindle Edition.
If you read these quotes (which are from an essay in that book written by Pascal Denault) in the context of my three linked posts above you'll see what the republication (not reestablishment, but republication) of the Covenant of Works at Sinai is about.
The reason paedo-baptists (those who believe in and are panicked to protect the doctrine of infant baptism) refuse to see what is written above is because they MUST maintain a parallel between circumcision and ritual water baptism (when the real parallel there is circumcision of the flesh vs. circumcision of the heart, which is regeneration by the word and the Spirit), thus they actually say that the Old Covenant the apostle Paul mentions is the Abrahamic Covenant, AND that it is of the Covenant of Grace, making Paul in effect say the New Covenant does away with the New Covenant (which logically is on a par with their other necessary ad hoc violator of the law of non-contradiction doctrine that one can be in the Covenant of Grace and not in the Covenant of Grace at the same time).
Basically, in all this they downgrade the fact and reality of the doctrine of supernatural, monergistic regeneration by the word and the Spirit, and as a by product of that they have a man-centered view of the word of God itself (accepting atheistic, scholar-constructed versions over the pure and whole, inerrant, Holy Spirit preserved received Hebrew and Greek text in sound translation, which in English is the Authorized, King James, Version; the one they tacitly recognize as the Standard in all their translating activities despite themselves).
Anyway, this downgrading of regeneration (being born again) causes their churches to be dead zones, at best shallow, at worst Satanic. Spiritually dead either way. Their standard - and very on-the-mark, except on infant baptism - theologian, Louis Berkhof, wrote a surprising essay on this that they refuse to publish, yet lo and behold it is available to their dismay on the internet for anyone to read and be pleasantly - hopefully - surprised at.