One of the ongoing debates amongst Christians is the question around the place of Mosaic law (torah) under the "new covenant" in Jesus. How and to what extent does it still apply to Christians? And what was the purpose of it for the Jews?
This is massive question, and it is an important one. One of the classic ways to handle the question is to understand that there are three different ways to categorise the various commands and regulations under Moses: moral, ceremonial, civil. This is an approach that Calvin uses.
In recent times there have also been fresh ways to think about the "works of the law", by proponents such as N T Wright. Is this phrasing more about morality and merit, or is more about some kind of badge of identity? Interestingly Calvin also uses this terminology of "badge" or "mark" in relation to ceremonial law.
Below are some pertinent quotes from Calvin's commentary on Ephesians 2:14-16, where Paul speaks about law and commandments being abolished:
And breaking down the middle wall of partition. To understand this passage, two things must be observed. The Jews were separated, for a certain time, from the Gentiles, by the appointment of God; and ceremonial observances were the open and avowed symbols of that separation. Passing by the Gentiles, God had chosen the Jews to be a peculiar people to himself. A wide distinction was thus made, when the one class were “fellow-citizens and of the household” (Ephesians 2:19) of the Church, and the other were foreigners...
Bounds were thus fixed by God to separate one people from the rest; and hence arose the enmity which is here mentioned. A separation is thus made. The Gentiles are set aside. God is pleased to choose and sanctify the Jewish people, by freeing them from the ordinary pollution of mankind. Ceremonial observances were afterwards added, which, like walls, enclosed the inheritance of God, prevented it from being open to all or mixed with other possessions, and thus excluded the Gentiles from the kingdom of God.
But now, the apostle, says, the enmity is removed, and the wall is broken down. By extending the privilege of adoption beyond the limits of Judea, Christ has now made us all to be brethren...
Having abolished in his flesh the enmity. The meaning of Paul’s words is now clear. The middle wall of partition hindered Christ from forming Jews and Gentiles into one body, and therefore the wall has been broken down. The reason why it is broken down is now added — to abolish the enmity, by the flesh of Christ. The Son of God, by assuming a nature common to all, has formed in his own body a perfect unity.
Even the law of commandments contained in ordinances. What had been metaphorically understood by the word wall is now more plainly expressed. The ceremonies, by which the distinction was declared, have been abolished through Christ. What were circumcision, sacrifices, washings, and abstaining from certain kinds of food, but symbols of sanctification, reminding the Jews that their lot was different from that of other nations; just as the white and the red cross distinguish the French of the present day from the inhabitants of Burgundy. Paul declares not only that the Gentiles are equally with the Jews admitted to the fellowship of grace, so that they no longer differ from each other, but that the mark of difference has been taken away; for ceremonies have been abolished. If two contending nations were brought under the dominion of one prince, he would not only desire that they should live in harmony, but would remove the badges and marks of their former enmity. When an obligation is discharged, the handwriting is destroyed, — a metaphor which Paul employs on this very subject in another Epistle. (Colossians 2:14.)
Some interpreters, — though, in my opinion, erroneously, — connect the words, in ordinances, with abolished, making the ordinances to be the act of abolishing the ceremonies. This is Paul’s ordinary phrase for describing the ceremonial law, in which the Lord not only enjoined upon the Jews a simple rule of life, but also bound them by various statutes. It is evident, too, that Paul is here treating exclusively of the ceremonial law; for the moral law is not a wall of partition separating us from the Jews, but lays down instructions in which the Jews were not less deeply concerned than ourselves. This passage affords the means of refuting an erroneous view held by some, that circumcision and all the ancient rites, though they are not binding on the Gentiles, are in force at the present day upon the Jews. On this principle there would still be a middle wall of partition between us, which is proved to be false.
That he might make in himself. When the apostle says, in himself, he turns away the Ephesians from viewing the diversity of men, and bids them look for unity nowhere but in Christ. To whatever extent the two might differ in their former condition, in Christ they are become one man. But he emphatically adds, one new man, intimating (what he explains at greater length on another occasion) that “neither circumcision, nor uncircumcision, availeth anything,” (Galatians 6:15) but that “a new creature” holds the first and the last place. The principle which cements them is spiritual regeneration. If then we are all renewed by Christ, let the Jews no longer congratulate themselves on their ancient condition, but let them be ready to admit that, both in themselves and in others, Christ is all.
