The Old Testament Law is super important. It’s just like all scripture: God breathed and useful for teaching, rebuking, correcting and training in righteousness.
Jesus said that He DID NOT come to abolish the Law but to fulfill it. So anybody who says, “Jesus came to get rid of the Law” is misinformed.
Now, we don’t follow all those rules today. Why is that? Why did Jesus go around performing “illegal activities” on the Sabbath? Why did God tell Peter to eat a bunch of unclean animals in his vision?
There are three types of Old Testament law: Ceremonial, Civil, and Moral Law. And I’ll quote some people that are smarter than I am:
God gave the ceremonial laws to the people of Israel as a means of guiding them in their worship of him. These laws include the various sacrifices for sin, circumcision (Gen. 17:10), priestly duties (Lev. 7:1–37), rejection of certain foods (e.g., pork (Lev. 11:7–8) and shellfish (Lev. 11:9–12)), and the cleanliness code (i.e., on cleansing lepers (Lev. 14:1–32), and the like.
The ceremonial laws served a temporary purpose and foreshadowed the coming of Jesus (Dan. 9:27; Col: 2:17; Heb. 10:1) until they were fulfilled and abolished in him.
Today, we are no longer required to follow them and are free to eat bacon wraps and wear clothes made with multiple fabrics. In other words, we don’t have to ceremonially purify ourselves for God; he does that for us through faith in Christ.
God gave the nation and theocracy of Israel civil laws to guide their daily living, political affairs, and judicial system (Exod. 21–23:9; Lev. 19:35; 24:17–23). Today, these civil laws and their punishments are no longer applicable. They expired when the people of God were no longer determined by their ethnicity or geographic location, but rather through faith in Jesus Christ (Gal. 3:7–9, 29).
Today, God’s people assemble together as a church from every nation, tribe, and language (Rev. 7:9). His church is not a nation-state like Israel or identified by a particular political party.
Today the church does not deal with sins the same way as Israel once did. The penalties have changed. The church deals with sin “by exhortation and, at worst, exclusion from membership” (e.g., 1 Cor. 5), not stones and fire.
God not only gave us moral laws like the Ten Commandments (Exod. 20:1–17), but he wrote them on our heart (Rom. 2:14–16). And these laws have not been abolished in Christ (Matt. 5:17–19).
While the moral law of God does not provide salvation (Rom. 3:20; 6:14; Gal. 5:23), it does continue to be used as a mirror reflecting the perfect righteousness of God, a means of restraining evil, and a way to reveal what’s pleasing to God.
Today the moral law of God is still in force and it has much to say about loving our neighbor (Lev: 19:18; cf. Matt. 19:19), taking care of the poor (Deut. 15:4; cf. Acts 4:34), and staying sexually pure (Exod. 20:14; cf. 1 Cor. 6:9).