It is my understanding that the law remains, and only the sacrificial ordinances were abolished because Christ shed his blood for us once and for all.
The difficulty in declaring that only a portion of the Mosaical Law was ended by Christ is in determining where to draw the line. One of the proofs that the Hebrew writer uses to argue that the Old Law is no longer in effect is to point out the weakness inherent in animal sacrifices. "For the law, having a shadow of the good things to come, and not the very image of the things, can never with these same sacrifices, which they offer continually year by year, make those who approach perfect. For then would they not have ceased to be offered? For the worshipers, once purified, would have had no more consciousness of sins. But in those sacrifices there is a reminder of sins every year. For it is not possible that the blood of bulls and goats could take away sins" (Hebrews 10:1-4). The repeated sacrifices were replaced with one perfect sacrifice. "Previously saying, "Sacrifice and offering, burnt offerings, and offerings for sin You did not desire, nor had pleasure in them" (which are offered according to the law), then He said, "Behold, I have come to do Your will, O God." He takes away the first that He may establish the second. By that will we have been sanctified through the offering of the body of Jesus Christ once for all" (Hebrews 10:8-10). But you missed the point of argument. The entire Law had to be replaced because the system of sacrifice was changed.
For example, under the Old Law there were specific sacrifices required to be offered on the Sabbath. "And on the Sabbath day two lambs in their first year, without blemish, and two-tenths of an ephah of fine flour as a grain offering, mixed with oil, with its drink offering - this is the burnt offering for every Sabbath, besides the regular burnt offering with its drink offering" (Numbers 28:9-10). Often people argue the keeping of some of the Sabbath day regulations, but discard others. Yet in the Old Testament, they are separated. How does one keep the Sabbath by only keeping a portion of the commandments?
In the New Testament we are warned that attempting to keep a portion of a Law obligates a person to keep the entire Law. "For whoever shall keep the whole law, and yet stumble in one point, he is guilty of all. For He who said, "Do not commit adultery," also said, "Do not murder." Now if you do not commit adultery, but you do murder, you have become a transgressor of the law" (James 2:10-11). Paul uses this principle when arguing against circumcision. "Stand fast therefore in the liberty by which Christ has made us free, and do not be entangled again with a yoke of bondage. Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing. And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law. You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace" (Galatians 5:1-4). Here then we learn that it was not just the laws of sacrifices which were replaced. Circumcision, the sign of the covenant, was also removed.
Does this mean we are no longer under any law? The answer is clearly no. Jesus took away the first law in order establish a second law. We are not under the law of Moses but under the law of Christ (Galatians 6:2). This new law has many features which are similar to the old law. There are still laws against lying, adultery, fornication, and stealing. Such would be expected because the new law comes from the same God as the old law. Yet because the new law was established upon better promises, there are features which differ from the old law. This was a point Jesus made to the woman at the well. "The woman said to Him, "Sir, I perceive that You are a prophet. Our fathers worshiped on this mountain, and you Jews say that in Jerusalem is the place where one ought to worship." Jesus said to her, "Woman, believe Me, the hour is coming when you will neither on this mountain, nor in Jerusalem, worship the Father"" (John 4:19-21). Under Moses' law, worship took place at the temple, but under Christ's law worship is not restricted to a fixed location. Here again is another change between the laws.
As you read through the book of Hebrews, you will find that the author argues that the laws must change because a variety of features changed. He argues that the source changed (Hebrews 1:1-2); the founder changed (Hebrews 3:2-6); the High Priest changed (Hebrews 3:1; 4:14-5:10); the priesthood changed (Hebrews 7:1-25); the covenant changed (Hebrews 8:6-13); the worship service changed (Hebrews 9:1-28); and the sacrifice changed (Hebrews 10:1-18). When something changes, it requires a change in the law, as the writer pointed out concerning the priesthood. "For the priesthood being changed, of necessity there is also a change of the law" (Hebrews 7:12).
The law of Moses was a complete package which was replaced by another better package. Why should we want to return to the old model?