Jesus fulfilled the law and has become our Sabbath, our rest from works, as we are saved by His grace (Hebrews 4:3-4). The idea of resting from our own works and entering into the Sabbath (rest) with God fits in with the teaching that when we are converted we forsake our own will to do the will of God. Nowhere in the New Testament does it say to keep the Sabbath Day as the people of Israel did under the Old Testament. Instead, we follow the examples of the Church in the Book of Acts and meet to break bread on the First Day of the week, in remembrance of Christ’s resurrection from the dead.
While we look to the books of the Old Testament for a knowledge of how God thinks and acts, for inspiration from people of faith, for comfort in the psalms, or wisdom in its proverbs, we base our doctrines on the New Testament, and do not keep teachings or practises found only in the Old Testament, such as:
The apostles recognised these principles in Acts 15, where they decreed that gentile believers do not need to be circumcised, but have to keep themselves from fornication, from eating food offered to idols, from eating animals strangled to death, and from eating blood. In Acts 10, Peter was taught that he could and should keep company with gentiles, and eat foods that the Jews had previously considered unclean.
Both the Old Testament and the New Testament make it very clear about which covenant (testament) is superior:
Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith the LORD: But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
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: Not according to the covenant that I made with their fathers in the day when I took them by the hand to lead them out of the land of Egypt; because they continued not in my covenant, and I regarded them not, saith the Lord. For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people: And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest. For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more. In that he saith, A new covenant, he hath made the first old. Now that which decayeth and waxeth old is ready to vanish away.