This question is as important as it is confusing.

Many don’t know where to start and end on this topic. But the answer really is not that complicated if you consider the purpose of the laws.

Just because something is commanded or modeled in the Bible does not automatically mean that it applies to us in the 21st century. Now before you question my belief in the applicability of all of God’s Word to all of life (2 Tim 3:16), consider the gift of tongues.

I do not practice the gift of tongues because the Bible is quite clear on their purpose. Tongues were meant for a short period of time for a very specific purpose. They were given as a sign for unbelievers in the early church (1 Cor 14:22). God used them to confirm that He offered salvation to the Jews (Acts 2), the Samaritans (Acts 8), the Gentiles (Acts 10), and to those who followed John the Baptist (Acts 19). But now that we have the New Testament, we no longer need a miracle to confirm this truth. With the passing of the apostles so passed the gift of tongues and other miraculous gifts sometimes called "sign" gifts. It is significant that in his final three letters (1 Timothy, 2 Timothy and Titus), all written to pastors, Paul never once commands or even mentions the sign gifts. Their unique purpose limited the longevity of their use. 

The same truth applies to the Old Testament commandments. A few days ago someone at one of our on campus Bible studies asked if we have to keep the Ten Commandments. Let me ask you: Is it okay to murder? Is it okay to tell a lie? Of course not. We obey these commandments not only because our conscience tells us to but because they are commanded in the New Testament. They were specifically given to the church to obey.

Only one out of the Ten Commandments was not repeated in the New Testament: Keep the Sabbath. This was a law given to Israel specifically, but never to Christians under the New Covenant. The principle of taking time to rest in the Lord and worship Him and focus on spiritual growth is taught all over the New Testament, but the actual command to keep the Sabbath does not apply. Besides, if we think it applies to going to church then we need to follow the Seventh Day Adventist approach (or that of the Jehovah Witnesses) and worship on Saturday. The Sabbath was the seventh day of the week, not the first.

Then why do we worship on Sunday? Because that’s what the apostles did. They set the model and we follow it—not because it’s commanded (it never is) but because that is the example set before us. They started worshipping on the first day of the week in honor of Christ’s resurrection which was on Sunday. And no, I do not believe it is sin for a believer to work on Sunday. You cannot defend this position from Scripture. The Bible commands us to not forsake our own assembling together as is the habit of some, but it doesn’t tells us on what day to do this. This means every believer everywhere should be attending a church on regular basis (not matter what day they meet), and a church that is ruled by elders (1 Tim 3; Titus 1) who are equipping the people for the work of the ministry (Eph 4:11-12). This means that a weekly Bible study or get together of believers cannot replace a believer’s responsibility to attend a local, elder-ruled, God-centered, Bible-preaching, lost-seeking church.

Okay, so back to the main topic: which commands of the Old Testament must you obey? The Old Testament laws can be divided into three helpful categories: ceremonial, civil, and moral. The ceremonial laws dealt with cleansing, the civil laws covered government type issues, and the moral laws coincided with principles of conscience. Here’s an example of a ceremonial law: If you developed leprosy on your left earlobe and the priest diagnosed it as infectious, you’ve have to stay outside the camp for seven days (Lev 13). This is the ancient example of quarantine. If after seven days the green spot looked better then you’d wash your body and clothing and offer sacrifices so that you could be announced clean. Hundreds of laws like this (even dealing with women’s menstrual cycle and men’s wet nights) were given to Israel.

The second category of Old Testament laws were civil. We must remember that Israel was a theocratic nation. That means they were not ruled by a plutocrat (a rich person) nor a democrat (the people), but a theocrat, God Himself. Laws like stoning for committing adultery or the Day of Atonement were civil laws. We don’t obey these laws because we don’t live under a theocratic government. Yes, God is our King, but he has also put us under a human government with laws that we are to obey. In Romans 13 Paul tells us to obey the laws of the land. This means we can’t drive over 65 mph on the freeway because the government tells us not to. You don’t find speed limit laws in the Old Testament just like you don’t find stoning-the-child-for-blaspheming-his-parents laws in American government.

The final category is moral laws. Nine of the Ten Commandments are moral laws. Don’t covet. Honor your parents. Worship God alone. All of these are moral principles that are universal to every human and every nation. Note also that these moral laws were repeated in the New Testament. Christ’s perfect life and sufficient death did away with the need for obeying the civil and ceremonial laws. They no longer apply because though God has not changed, His program has. That’s why we don’t offer sacrifices, confess to priests, or observe the Passover. Those were imperfect foreshadows of the perfect fulfillment brought through Jesus Christ. Christ is the perfect sacrifice (John 1:29), our one and true High Priest (Heb 7:26), and His suffering on the cross is our ultimate Passover for all eternity (1 Cor 5:7).

A huge help in sorting through this difficult subject is understanding the distinction between the church of the New Testament and Israel in the Old Testament. “Testament” means covenant. Our Bibles are divided into the two covenants: the old one and the new one. John the Apostle wrote, “For the Law was given through Moses, grace and truth were realized through Jesus Christ” (John 1:17). In one verse John made a clear distinction not only between two covenants but between two peoples.

Israel was called out as a nation set apart by God to obey His laws to be the nation through whom the Messiah would come. Well, the Messiah came. That’s why we are under a different covenant: the New one. Today, a believer is part of the body of Christ called the church. Not every Israelite was saved but every true Christian is saved. God never gave the ceremonial and civil laws to the church—He only gave them to Israel.

Consider just a few of the many differences between the Israelites in the Old Testament and the church today:

So do these Old Testament laws apply to us? Yes and no. Directly, no. Ultimately, yes. Paul said that all Scripture is applicable to every believer (2 Tim 3:16; 1 Cor 10:6). Although we don't obey all the Old Testament laws, without understanding their purpose, our spiritual growth is greatly restricted. How could we fully appreciate the life and death of Christ if we did not understand the thousands of prophecies and foreshadows given under the Old Covenant to predict His coming? How could we appreciate the depth of God's grace through Jesus Christ if we were not first struck with the awesome holiness of God demonstrated through the 613 commandments given to Israel to set them apart as a holy nation, different from the world?

God does not change, but His methods do.