Let’s begin with a few general principles for interpreting the OT law.
1. Not in Use Today
These OT laws were not given for all time and all cultures. Instead, these were given for that time and that culture. That is, the Bible itself teaches that the OT law is no longer in practice today. British scholar John Wenham writes,
It needs to be clearly understood that a defence of the morality of Old Testament law in Old Testament times does not necessarily imply that these laws should be reimposed today. Christians were (and are) bidden to study the Old Testament diligently, but nowhere is it said that they should go into all the world and impose its entire law on every society.
The OT predicted a time when these laws would become unnecessary for Israel. For instance, Jeremiah writes, “I will put My law within them and on their heart I will write it” (Jer. 31:33 NASB). Moreover, Ezekiel writes, “I will put My Spirit within you and cause you to walk in My statutes, and you will be careful to observe My ordinances” (Ezek. 36:27 NASB; see also Deut. 30:6). In other words, the OT claimed that these laws were not meant to be indefinite; instead, they would eventually become unnecessary.
The New Testament (NT) agrees with this view. In fact, the NT explains that these laws have fulfilled their purpose, because Jesus fulfilled them:
(Mt. 5:17-18 NASB) Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill. 18 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.
(Rom. 10:4 NASB) For Christ is the end of the law for righteousness to everyone who believes.
(Rom. 6:14; 7:6 NASB) For sin shall not be master over you, for you are not under law but under grace… But now we have been released from the Law, having died to that by which we were bound, so that we serve in newness of the Spirit and not in oldness of the letter.
(Gal. 3:24 NASB) Therefore the Law has become our tutor to lead us to Christ, so that we may be justified by faith.
(Heb. 8:13 NASB) When He said, “A new covenant,” He has made the first obsolete. But whatever is becoming obsolete and growing old is ready to disappear.
Repeatedly, throughout the NT, we read that the law has been fulfilled in Christ, because of Jesus’ finished work on the Cross. The OT Law was not a bad thing that has now been abolished, but rather, it was a good thing that has now fulfilled its purpose. The purpose of the law was to point humanity towards their need for Christ (Gal. 3:24).
Consider a man who goes away to war, leaving behind his newlywed wife and newborn baby. When he’s gone, he writes dozens of love letters, telling his wife how much he loves her and cares about her. Finally, when the man returns, he arrives with flowers on the front porch. Now, ask yourself: now that the man is back, what would be the purpose of the love letters? Would the woman leave the man to go back and read his letters? If she abandoned the man for the letters, this would be absurd! In the same way, Christians read through the OT law today, but they should never fall back under law and abandon Jesus. Instead, they should read the OT law, remembering the high price that Jesus paid on the Cross.
When we flip through the NT, we see many examples of how the purpose and use of the law changed after the Cross.
In the OT law, Gentiles needed to be circumcised to be allowed into the community of God (Gen. 17:14). However, when Jewish Christians argued for the necessity of circumcision (Acts 15:1, 5), the early Christian leaders debated this intensely (Acts 15:7). In the end, they determined that Gentiles did not need circumcision (Acts 15:23-29).
2. False Teaching
Israel executed false teachers for leading people astray (Deut. 13:5; 18:20; Lev. 19:26; Ex. 22:18). However, in the NT, Simon (the magician) was not stoned to death; he was converted to Christ (Acts 8:9-13). Later, when he made drastic doctrinal errors, he was not put to death; he was rebuked and corrected by Peter (Acts 8:18-23). Likewise, Paul came across a “Jewish false prophet” named Bar-Jesus. And yet, instead of stoning the man to death, Paul rebuked him (Acts 13:10) and temporarily blinded him (Acts 13:11).
In 1 Corinthians 5, a man is caught in adultery (sleeping with his stepmother). Paul doesn’t call on him to be executed, as the OT law prescribed (Lev. 20:10). Instead, he calls for removal from fellowship.
4. Submission to Secular Government
In the OT, the people of God lived in a theocracy –not a democracy. “Theocracy” comes from the Greek words theos (“God”) and archos (“ruler”). God ruled this nation personally. However, after the Cross, God commands his people to submit to secular government. For instance, Paul writes, “Every person is to be in subjection to the governing authorities” (Rom. 13:1a NASB). Peter writes, “…Honor the king” (1 Pet. 2:17 NASB). Moreover, Jesus said “My kingdom is not of this world. If My kingdom were of this world, then My servants would be fighting so that I would not be handed over to the Jews; but as it is, My kingdom is not of this realm” (Jn. 18:36 NASB; see also Mk. 12:17).
2. Not the Final Law, but the First Law
The OT civil law was not perfect or ideal. This might come as a shock to many Bible believers (“How could a perfect God give imperfect laws?”), but it’s true. When God gave his civil laws to the nation of Israel, he was not trying to create a perfect society, once and for all. Instead, he was trying to improve society and “take what he could get.” Put another way, the OT civil law wasn’t God’s final law; it was simply his first law. If you are trying to teach a kid math, you don’t begin with calculus; you begin with addition. In the OT civil law, God was condescending to human culture to meet them where they were at.
Jesus explains this for us in the Gospel of Matthew, when he says,
Because of your hardness of heart Moses permitted you to divorce your wives; but from the beginning it has not been this way (Mt. 19:8 NASB).
Notice that Jesus did not say that God desired divorce. God doesn’t desire divorce. In fact, he hates divorce (Mal. 2:16). But, if God hates divorce, then why does he “permit” it in the OT law (Deut. 24:1-5)? Jesus tells us. He said that God allowed this because of their “hardness of heart.” We can extrapolate this principle to the entirety of the OT civil law. We might say that God didn’t want slavery, but he permitted it. He didn’t want war crimes, but he permitted it. He didn’t want severe punishments, but he permitted them.
This does not mean that moral relativism is true (i.e. morality is relative to human culture or personal preference). It isn’t. The standard for morality has its foundation in the perfect nature of God, which does not change. However, God was not implementing a perfect society, when he was stooping down into human culture in the ancient Near East. He was drastically improving the standard, while at the same time “permitting” laws that weren’t perfect.
Think about a modern example. When Abraham Lincoln issued the Emancipation Proclamation, this did not immediately change the culture of slavery in the South. Even though laws were passed years ago, racism still continues through the South to this day. Laws don’t change people’s hearts. Likewise, we need to understand that the OT law was also never designed for this purpose.
Are there any universal moral imperatives in the OT? Of course. One way of identifying these is by comparing them with the NT imperatives. For instance, adultery is mentioned in the OT law, and it is repeated in the NT imperatives, as well. This is one way that we can distinguish universal moral imperatives for all time with civil and cultural imperatives for that time.
3. Case Law
We find another principle for interpreting OT law in what is called case law. Case laws were laws that describe specific events or “cases” that come up in society. These laws usually begin with the word “If…” That is, if such-and-such happens, then you should do such-and-such. Let’s look at a few examples.
(Ex. 22:1 NASB) If a man steals an ox or a sheep and slaughters it or sells it…
(Ex. 21:18 NASB) If men have a quarrel and one strikes the other with a stone or with his fist…
(Ex. 21:7 NASB) If a man sells his daughter as a female slave…
(Deut. 21:15 NASB) If a man has two wives…
Notice, these are not prescriptions. God doesn’t approve of stealing (Ex. 20:15), but he created a case law in case somebody steals. God doesn’t approve of fighting, but he created a case law in case somebody does (Ex. 21:18). One mistake of the New Atheists is that they interpret case laws, as though they were commands. However, case laws were not commands; they were concessions. God knew that people would break the law, so he wrote case laws for when this would happen.
4. OT Law was Better than Its Neighbors
While many people are shocked at the OT law, we need to compare it to the other laws in the ancient Near East. Some laws in the OT are almost word-for-word identical with the ancient Near Eastern laws. For instance, one of the Eshnunna laws (§53) is almost verbatim with Exodus 21:35 (i.e. what to do if an ox hurts another man’s ox). This similarity shouldn’t surprise us. Acts 7:22 says that Moses was a well-educated man, fully “educated in all the learning of the Egyptians.” This education must have included legal codes, making him well acquainted with the neighboring legal codes.
This being the case, it seems clear that Israel’s laws could have conformed to the neighboring nations. But, as you’ll see, Israel’s laws were far better than the barbaric actions surrounding them.
5. Knowing Too Much or Too Little?
As a 21st century, Western reader, we are light years away from the culture and time period in which these OT laws were generated, and this often leads to confusion. Think about current cultural issues for a moment. Today, in some cultures, it is considered proper to belch loudly after dinner. In other cultures, it is perfectly appropriate for two men to walk down the street holding hands, as a sign of heterosexual affection. While Westerners are often shocked at these customs, this is only because we are often ignorant to the customs of other cultures.
In the same way, as readers far removed from both the time and place of the ancient Near East, we will often find ourselves confused at what we read. Keep this final principle in mind: Our problem is not that we know too much –but too little! Time and time again, you will find that many problems in the OT law are not moral issues; instead, they are culturalissues. When you uncover the cultural milieu of the ancient Near East, you often find that their practice is actually similar to our own.
 It’s interesting that post-modern critics would hurl moral accusations at the Bible, when they believe that morality is generated from culture. On what basis do they attack these atrocious laws, when they believe that law is relative to the culture in which it is found?
 Wenham, John William. The Goodness of God. Downers Grove, IL: InterVarsity, 1974. 97.