You have heard that there were/are two main covenants in Scripture; the Covenant of Works, which included the Adamic, Noahic, Abrahamic, Davidic, and so on and so forth, as many as seven, and the Covenant of Grace, which came through Jesus who is the Christ. This is an unfair distinction to make, because it should be fairly clear that the Covenant that God constantly affirmed with His people included both Law ( Works ) AND Grace! When Adam was created, for instance, God did not have to provide a mate for him, but because He loved His Creation, He gracefully brought Eve to Adam! Noah, along with his family, was saved from the whelming flood through the Grace of the Ark, which was typical of salvation in the Christ! The Abrahamic and Davidic, and other various iterations can be seen to involve both an undeserved Grace and a rather weak and iffy obedience to that covenant.
If you have read any of my previous posts on the subject, you are probably familiar with the concept that I along with others have put forth, the fact, as I believe, that the Creation Account in Genesis 1 is not so much an account of the physical creation, as it is an account of the forming of the Covenant, first with the Land ( Temple ), then with Man in the Land ( Adam ). I have posited before that the 'Let there be Light' in Genesis 1:3 was the initiation of this Covenant, and that God's 'Let Us make Man in Our Image' in Genesis 1:26, the ratification of His Covenant with Man!
To be sure, Scripture does, in a sense, speak of two different, or separate covenants! The first recorded as such was made with Abraham, beginning from Genesis 12 and on, but the main covenantal focus in the Hebrew Scriptures is the Mosaic Covenant, which is what has come to be known as the Covenant of Works! This Covenant is most famously enumerated in Exodus 20, with the giving of the Law in the form of the Ten Commandments, or Ten Words. The blessings and cursings of Deuteronomy chapter 28 are also one of the more famous ( or 'infamous'? ) examples of the Mosaic, or Covenant of Works.
Some study has been done of the notion that this first ( covenant ) was not one of marriage, as had previously been thought, but was actually one of betrothal. In the Hebrew or Jewish mindset, as I understand it, this is not quite like an engagement, though obviously related,but had greater and deeper ramifications as to the legality of the marriage. For instance, when Joseph found out that his betrothed was with child, Scripture records that he was told by God 'Joseph, son of David, do not be afraid to take to you Mary your wife, for that which is conceived in her is of the Holy Spirit'. Even though they were not legally and officially married yet, they were already bound together as husband and wife. The Covenant had been inaugurated with the betrothal, but would not be consummated until the marriage had occurred!
As we have seen, and can easily ascertain throughout the Hebrew Scriptures, even though there were always consequences for wrongful actions; Grace has always played a major role in God's dealings with His covenant people! If not for Grace, Israel under that first ( covenant ) wouldn't have lasted as long as She did. Ezekiel 36:22 records, 'Therefore say to the house of Israel, ‘Thus says the Lord God: 'I do not do this for your sake, O house of Israel, but for My holy name’s sake, which you have profaned among the nations wherever you went.'
As I alluded to earlier, the fact that there is really but One Eternal Covenant in the record of Scripture, is not only scripturally sound, but theologically sound as well, and it just makes sense! We know that God does not change, and if we posit that there were two totally different covenants, one of ( by ) Works and one of ( by ) Grace, then we must see, by implication, that God Himself changed His modus operandi over the ages. This, in fact, if I'm not mistaken, is what dispensationalism teaches! God has always dealt with His people in Grace, although through Law, and He will continue for the ages of the ages to deal with them in the same way! Scripture tells us that 'He chastens those whom He loves'. Like any good Father, He disciplines, through the application of Law, His people, but He always deals with us in Grace!
In conclusion then; we cannot have Grace without Law, and vice-versa, the Law of God operates through His Grace!! If we claim that there is no longer any Law then we cannot have Grace, since Grace, being un-merited favor, is receiving what we do not deserve. If there is no Law saying that we must do this or that, then there must be no Grace to give us what we don't deserve! The apostle Paul wrote to the Roman Christians, 'For until the law sin was in the world, but sin is not imputed when there is no law.' ( Romans 5:13 )
Charles Haddon Shank