The Old Testament Law was to point out the people's sins, and to show them it is impossible to please God by trying to obey all His laws.
The beginning of the New Testament, (New Covenant) brought over six hundred Old Testament Ceremonial Laws to an end; Leaving the civil and moral laws to guide man’s conduct, and to identify what God considers to be sin.
There has been much debate over these laws, and how they apply. For the Christian, the civil and moral laws reveal the nature and will of God, and how people are to live.
“For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise,
Why then the law? It was added because of transgressions, until the offspring should come to whom the promise had been made, and it was put in place through angels by an intermediary,”
(The Apostle Paul, Gal 3:18-19, ESV).
The Covenant with Abraham shows that faith is the only way to enter into Heaven. God's promise to Abraham was through faith, while the Old Law focuses on actions. Faith does not do away with the law; but the more we know God, the more obvious our sins become.
Christians are to depend on their faith in Christ alone for salvation. In fact, Christ is the only way given for mankind to enter into Heaven. (1 Tim 2:5)
The Old Testament Law identifies sin and teaches the need for salvation; God's grace gives us that salvation.
Part of the Jewish Law included the laws found in the Old Testament. When Paul said that non-Jews, (Gentiles) are no longer bound by these laws, he is not saying the Old Covenant laws do not apply today. He is saying, certain types of laws, as in the (over 600 Ceremonial laws and rituals), may not apply.
Ceremonial Law: This type of law related to Israel's worship. (Lev 1:1-13) The laws pointed forward to Jesus Christ and were no longer necessary after Jesus' death and resurrection. Though we are no longer bound to them, the principles behind the ceremonial laws, to worship and love God, still apply.
Civil Law: This law dictated Israel's daily living (Deut 24:10-11); but modern society and culture are so radically different that some of these guidelines cannot be followed specifically. The principles behind the commands are to guide our conduct.
Moral Law: The moral laws are direct commands of God. A good example are the Ten Commandments (Ex 20:1-17). The moral laws reveal the nature and will of God, and still apply to us today. We do not obey this moral law as a way to obtain salvation, but to live in ways pleasing to God. (segments from, "Life Application Study Bible")
The Old Testament Law is where God reveals His nature, His will/lifestyle for humanity, His moral laws, and guidelines for living. But we cannot go to Heaven by keeping that Law; we must be born again and trust in Jesus.
The Commandments of Jesus
Samuel L. Mills