The Law in the New Testament
Our Lord readily submitted to the whole of God’s law. At the time of the temptations, Jesus quoted from the law three times to resist and refute the devil (Mat.4:1-11). In dealing with the Pharisees, who had accused the disciples of being in breach of the elders’ traditions, Jesus quoted from the law, highlighting their hypocrisy (Mat.15:1-14). In teaching the disciples, Jesus taught from the law (Luke 24:25-27).
Jesus came and spoke as a king. He spoke “with authority” (Mat.7:29). All kings have laws and rules. Any kingdom without law presupposes anarchy. Jesus submitted to and taught from the law, because it was His law:
the warfare of Jesus was not against Moses. It was against the scribes and Pharisees who perverted Moses. It is a perversion of Scripture to separate the law and the prophets from Jesus. The Mount of Transfiguration witnessed to their unity.
Jesus made His attitude towards the law abundantly clear, in Mat.5:17-18: “Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfil. For truly I say to you, until heaven and earth pass away, not the smallest letter or stroke shall pass from the Law until all is accomplished.” This means that Christians should always reject careless and foolish assumptions about the law, which are not found in scripture. “Either God’s revealed law is sovereign in society or else autonomous man’s declared law is sovereign.”
When faced by Jesus, the scribes and Pharisees, who saw themselves as the guardians of the law, found themselves face to face with the law incarnate. Jesus manifested the true law of God, not the pharisaic versions of it, in all His being. In the hands of the religious leaders, the law had become a yoke of bondage (Gal.5:1), not the perfect law of liberty (James 1:25; 2:12).
Paul and the other apostles quoted from the law as though it was perfectly normative, to be obeyed by them and by us. (See Ro.15:4; I Cor.9:8-10; 14:34; Eph.6:1-3). Paul makes it clear (see Gal.1:13-17) that Judaism had been his former way of life, before becoming a Christian. Not anymore. Judaism was not the Old Testament faith. It was an attempt to implement an ancient heresy, justification by works, which is never taught in scripture.
Abraham is chosen by God and made just by God’s grace, not by his personal merit or works. Implicit and explicit in all that Paul continues to say is what Calvin briefly summarized thus: ‘there is no place in the church for any man who is not a son of Abraham.’ And we are sons of Abraham only by God’s grace through faith, not by blood or works. 
Five times in the Book of Galatians the apostle Paul names the issue he is vigorously contending with: Gal.2:16 (3 times); 3:11 and 5:4. Gal.2:16 says, “…a man is not justified by the works of the law but through faith in Christ Jesus, even as we have believed in Christ Jesus, so that we may be justified by faith in Christ and not by works of the law; since by the works of the law no flesh will be justified.”
Was Paul being critical of the law itself? No, for he said in another place, that “the law is holy, and the commandment is holy and righteous and good” (Ro.7:12). What the apostle Paul contended with and was critical of, were attempts by some within the church, particularly the Pharisees, to turn the law of God into a means of salvation– something which it was never designed for. “Galatians is a polemic against the Judaizers who insisted on the keeping of the ceremonial law as a way of justification” (cf. Acts 15:1, 5; Gal.5:1-6).”  North’s comments are also helpful here:
Paul was at war with Judaizers who were inside the church. They sought to bring gentiles under the mosaic ceremonial law, meaning laws associated with the priestly status of old Covenant, national Israel…Paul [in I Timothy 1:1-11] is identifying Judaizers, not gentile antinomians or gentile theonomists as the false teachers of Ephesus…Paul asks Timothy to tell them to stop teaching their version of Pharisaic legalism.
This helps us understand Paul’s comment, when he taught that “…you are not under law but under grace” (Ro.6:14). Judaism was a serious problem within the early church. Rushdoony is clear on this point:
Works are under a curse when they represent human activity apart from God and His sovereignty. Such works seek to vindicate man’s autonomy and to justify man before God and humanity. Such works posit the possibility of creating an order outside of God and thus represent the premise of Genesis 3:5, every man as his own god. Men can use God’s own law to attempt to justify themselves before God by uniting God’s law, as filtered through man’s hand, as a means of furthering their autonomy. 
This explains Paul’s question in Gal.4:21: “Tell me, you who want to be under the law, do you not listen to the law?” The Judaisers were effectively refusing the notion of God’s grace, believing that genealogical descent from Abraham and a superficial commitment to God’s law would both be a means of justification for them, when they should have known that no one can obey God’s law perfectly.
Judaism was thus hostile to the Christian faith, because it was:
a) Humanistic- Jesus said to the Pharisees, that “…you travel around on sea and land to make one proselyte, and when he becomes one, you make him twice as much a son of hell as yourselves” (Mat.23:15).
c) Hypocritical and racist-Mat.23:23-29; Jn. 4:9; 8:48.
d) A works based religion focused on the outward observance of Mosaic law, such as circumcision- Gal.6:12.
e) Religiously bigoted- Jn.9:24-34.
For the Pharisees, God’s law was a weapon of assault against anyone who did not fit their religious and political agenda, regardless of their innocence. But their criminal misrepresentations of God’s law only revealed their hypocrisy. It was they who were evil, not the law.
The law of God given to Moses, summarised in the Ten Commandments, was His gracious provision to a nation which had just emerged from the slavery of Egypt. It is the only true law of liberty mankind has ever had. Every other one has been a counterfeit. The Psalmist confessed as much when he wrote, “I will walk at liberty, for I seek Your precepts” (Ps.119:45).
Christians must confront the fact that God requires them to impose His law for the state upon all men, whether men like it or not. The universe is not a democracy, but a Kingdom. If Christians do not impose God’s laws upon non-Christians, then non-Christians will impose man’s laws upon Christians… The law of man bares its fangs of iron increasingly against the righteous.
 Rousas Rushdoony, “Institutes,” p.714.
 Gary North, “Inheritance and Dominion,” 1999, ch.18.
 Rousas Rushdoony, “The Gospel of John,” 2000, p.145.
 John Calvin, “Commentaries on the Epistle of Paul to the Galatians and Ephesians,” 1948, p.87.
 Rousas Rushdoony, “Romans and Galatians,” 2000, p.344.
Greg Bahnsen, “By This Standard,” 1991, p.309.
 Gary North, “Hierarchy and Dominion,” 2012, p.39, 47.
 Rushdoony, ibid, p.345.
 Andrew McColl, “The Great Christian Revolution,” chapter 3.
 James Jordan, “The Law of the Covenant,” 1984, p.29.