People talk about the "Old Covenant" and "New Covenant" as if there were only two covenants mentioned in the Bible. The fact is that there are many covenants. The major covenants mentioned in the Old Testament are...
- The covenant with Noah
- The covenant with Abraham
- The covenant at Mt. Sinai
- The covenant with David
None of those covenants were made with just one person. They were made with a person/people
and his/their descendants. So, what happens when a person is a descendant of more than one of those? For example, Isaac was a descendant of Abraham, as well as of Noah. The people who entered the Promised Land were descendants of Noah, Abraham and of the people who were at Mt. Sinai. Which covenant were they members of? Was it only the newest covenant that was valid, or the others as well? I believe that a person is a member of every covenant that was made with a group to which he belongs. We who are members of the New Covenant are all descendants of Noah, so we are also members of that covenant. As far as the "Old Covenant" (which I prefer to call the Sinai covenant) goes, to determine whether it applies to us, we simply need to see with whom it was made and whether we are part of that group.
The "with whom" part is pretty simple. It was made with all the people who were at Mt. Sinai and their descendants. The people who were there were the descendants of Abraham, Isaac and Jacob, and those who had joined themselves to them. Even though some were not physical descendants of Israel, they were collectively known as the Israelites, and their kingdom became known as Israel. Those who are part of Israel are members of the Sinai covenant. The other part - whether we are members of that group - is a little trickier. Most of us are not physical descendants of those who were present at Mt. Sinai when the covenant was made, but what about "joining ourselves to" Israel. The Bible says that Gentile Christians are "grafted onto" Israel (Rom. 11:11-24). If we are part of Israel by virtue of being grafted in, that would make us part of the covenants that apply to Israel. And then there is this...
Behold, the days are coming, declares the Lord, when I will make a new covenant with the house of Israel and the house of Judah (Jer. 31:31 ESV)
The New Covenant was made with "the house of Israel and the house of Judah". We can only be members of the New Covenant if we are part of the group that it was made with. If we are not either of the house of Judah or the house of Israel, then we cannot be members of the New Covenant. But if we are members, then we are also members of the Sinai covenant, since it was made with the same group of people. The law cannot be separated from the Sinai covenant. It is an integral part of it. If we are members of the New Covenant, then we are also members of the Sinai covenant and the law is applicable to us.
The TOG