The Two Covenants
We know that in all religious practices we must follow the teaching of God. God must direct our steps and we must allow Him to do so (Jer 10:23). When we read the Bible we must understand that the only way we can have eternal salvation is to obey ALL the commandments of God as they pertain to us. But which one's pertain to us today? Before we answer this question let's look at God's covenant relationship with His people.
The Bible Contains Two Distinct Covenants
We know that there are two covenants in the Bible because in Hebrews 8:7-8 we read: "For if that first covenant had been faultless, then should no place have been sought for the second. For finding fault with them, he saith, Behold, the days come, saith the Lord, when I will make a new covenant with the house of Israel and with the house of Judah." Here we can see that there are two covenants mentioned, but that the first had fault. It is because of that fault that God said a "new covenant" will be made.
Characteristics of the First Covenant
Here is what we know about God's first covenant with His people. First of all it was given to Moses. John said: "For the law was given by Moses, but grace and truth came by Jesus Christ" (John 1:17). Secondly, it was only a shadow of things to come. "For the law having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect" (Heb 10:1). From these scriptures we can already see some of the fault with that first covenant given to Moses. But that is not all. We can also learn that the old law was the ministration of death. We read from 2 Corinthians 3:7: "But if the ministration of death, written and engraven in stones, was glorious, so that the children of Israel could not stedfastly behold the face of Moses for the glory of his countenance; which glory was to be done away:" We further learn that it was a schoolmaster (Gal 3:24) and it could not justify (Rom 3:20). Therefore, seeing that the old law had fault we can now ask:
Is The First Covenant Binding On Men Now?
In Colossians 2:14 we read where it was blotted out. Paul said: "Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross;" It is written very clearly here that those ordinances under the law given to Moses have been "blotted out" and we can also see above where the old law was a schoolmaster (Gal 3:24), now it says we are no longer under a schoolmaster (Gal 3:25). The first covenant has been done away with (2 Cor 3:11). We can also read where it was disannulled and taken away. "For there is verily a disannulling of the commandment going before for the weakness and unprofitableness thereof" (Heb 7:18) and "Then said he, Lo, I come to do thy will, O God. He taketh away the first, that he may establish the second" (Heb 10:9).
Therefore we know now that God did away with the first covenant relationship that He had with His people and so we can also know the answer to our question that was asked in the first paragraph. But which one's (of God's commandments) pertain to us today? The answer is those commandments given to us under His new covenant that was given by Christ and those are found in the pages of the New Testament.