What Is the Purpose of the Old Testament Law?

If you watch a lot of Marvel movies, you’ll discover that overarching all the individual movies is a bigger narrative that ties all the individual movies together. We discover what fans refer to as “Easter eggs” scatter throughout each movie. These Easter-egg hints form a thread helping us to see how the larger story develops. Many movie fans will rewatch the movies, sometimes in chronological order so they can find the Easter eggs and better understand the larger narrative. The more you watch the movies, the more Easter eggs you pick up, the more you can see how the individual movies connect to each other and how they fill in the larger storyline.

Just like the Easter eggs scattered throughout the Marvel movies, the individual stories and chapters of the Bible are carefully curated, progressively revealing greater aspects of who Christ really is and what He has accomplished for humanity. He’s not Thanos, randomly finger-snapping humanity in some sort of ethnic cleansing. Jesus is our Savior, sovereignly and patiently restraining judgment on a world that deserves it because of our sin, so that some might be saved through repentance from sin and trust in Christ. As we read the law, or any other genre of Scripture, our task is to discover what Easter eggs are scattered about and how they contribute to the metanarrative (big story) of the Bible.

An Introduction to the Law

We often think of the law in two ways. In the general sense, the first five books of the Bible are referred to as the law. These five books are called the Pentateuch (PEN-tah-took), from two Greek words: pente, meaning “five,” and teuchos, meaning “books.” In the Jewish tradition, the Pentateuch is referred to as the Torah (a Hebrew word meaning “law” or “instruction”). More broadly, the law books are instructions, not merely rules. The opening pages of the Bible describe how God created a perfect place for God’s people to live under His rule. Genesis highlights God’s instructions to Adam and Eve in the garden, describing how He expected them to live in perfect communion with Him.

“For Israel and for us, the law points to Christ.”

When Adam and Eve failed, God purposed to create a new nation from one man, Abram, and his wife, Sarai, who would live under His rule. This young nation, commonly referred to as “the children of Israel,” grew but was taken captive by a ruthless ruler. God delivered them from their oppressors and guided them to the place of promise, where He would dwell with them as their God if they would love and obey Him. He set a leader before them, Moses, who would be His spokesperson before the people.

Most of the Pentateuch, from the middle of the book of Exodus to Leviticus, Numbers, and Deuteronomy, contains the instructions, or laws, that God gave to the people through Moses as he led Israel out of captivity and into the promised land of Canaan. God expected His people to live distinct from the pagan nations around them, holy to the Lord, and worshiping only Him. These laws were for their wisdom and understanding in the sight of the peoples around them, and for them to also teach their children to learn to fear God and obey Him (Deuteronomy 4:6, 9-10).

Another way we think of law in the Bible is the Ten Commandments. These formed the centerpiece of the Old Testament moral instructions meant to guide God’s people in how to love Him and one another well and how to live in joyful obedience to Him and joyful community with their neighbors.

So we have the “law books” (Genesis, Exodus, Leviticus, Numbers, Deuteronomy) that chronicle the establishment of God’s people, their early history, and journey to the Promised Land. And we have the “law” summarized in the Ten Commandments as instructions to govern how God’s people live under His rule. Throughout the Pentateuch and the entire Bible, echoes of the Ten Commandments permeate and serve as reminders for the people about God’s expectations. We don’t get very far in Scripture before we realize that God’s people were not very good at remembering and obeying.

The law teaches us that God has a standard, one we could never meet on our own, one that binds every heart to obedience. Whoever does not keep the entirety of the law is cursed (Galatians 3:10). So the law makes our inability bubble to the surface, showing us that no one can be justified by perfectly obeying the law. The law leaves us with a burning question: If no one can obey perfectly, then how can we be justified by God? The Bible teaches us that those who are counted righteous before God do so by faith in Christ, who “redeemed us from the curse of the law by becoming a curse for us” (Galatians 3:11-13). So when we read the law, we keep in mind that it points us to Christ’s once-for-all sacrifice for sin (Hebrews 10:12).

“God expected His people to live distinct from the pagan nations around them, holy to the Lord, and worshiping only Him.”

The laws presented in Scripture were handed down by God, in dialogue with Moses, who delivered them in a series of speeches to the people of Israel. These laws were ceremonial, civil, and moral in nature, but function as part of the larger story that chronicles the Israelites from their exodus from Egypt to their wandering in the desert (and eventually to the conquest of Jerusalem by Babylon). Why were all these laws written down for Israel and for us? Ligon Duncan explains,

So why did the law need to be written down? To restrain sin. Therefore, it can’t be the answer to the problem of sin. It’s there because of the problem of sin, not as the final answer to the problem of sin. The final answer to the problem of sin is the gospel! It’s the person and work of Jesus Christ, in His life and death and resurrection on our behalf, and our embrace of that by faith. That’s the good news that deals with sin.

We need the law not only to show us the problem of sin but also to lead us to the only solution for our sin problem, the Lord Jesus Christ and the deliverance He promises for those who repent of their sins and trust in Him. The law is the first act in the story of redemption, the first “Easter egg” that puts the rest of the Bible in motion. God created all things for His glory and gave His law as the standard by which all humanity would be measured. Since Adam’s and Eve’s sin, we are both unwilling and unable to obey God perfectly, so we enter the world as law-breakers. The Old Testament system of offering sacrifices to consecrate oneself to God, to repent and receive atonement for sin, and to restore fellowship and peace with God all required a blood sacrifice. An unblemished animal would serve as a substitute to die in the place of the one who offered it, in the place of the one whose sins required it.

When we study the law, we’re getting a handle on the first big Easter egg that will shape the entirety of Israel’s life as the people of God, as they constantly offered up sacrifices to God because of their sins. The law provides a picture of our own need for a substitute and points us to Christ as the once-for-all sacrifice for our sins (Hebrews 9:26:28). Our Bible study is enriched when we become familiar with the types of laws we see in Scripture, with how they instructed Israel’s conduct and worship, and with how the laws relate to us today.

Kinds of Laws

Often the law is sorted into three categories: moral law (truths that are timeless and guide our behavior), civil law (laws about governing people and laws that shape the legal system), and ceremonial laws (laws concerning holy days, especially to guide the priests in their duties). These categories help the Bible reader know which laws apply to us today (usually the moral ones because they are timeless) and which ones only applied to ancient Israel. However, if we believe that “all Scripture is breathed out by God and is profitable for teaching, for reproof, for correction, and for training in righteousness” (2 Timothy 3:16), then we must be able to make legitimate applications from the time of ancient Israel to our day and show how even obscure laws like “you shall not sow your field with two kinds of seed, nor shall you wear a garment of cloth made of two kinds of material” (Leviticus 19:19) might hold significance for us today. A law like this one makes it sound like a sin to wear a silk and cotton blend!

Careful reading of the law requires that we consider the purpose of the laws and determine how those purposes relate to our lives today. Obviously, not all the specifics of the Old Testament laws still apply to us. Nowadays, devout believers eat pork, wear clothes made of two types of fabric, don’t consider women ceremonially unclean after childbirth, and refrain from forcing women to drink bitter, poisonous water to see if the cheated on their husbands. But even if we contemporary believers don’t need to abide by each one of the detailed and specific laws given in the Pentateuch, those Old Testament laws are still as instructive for us today as they were for ancient Israel – just not in the same way. So, in the verse that says don’t mix fabrics, in our day we might consider how our spiritual holiness has practical implications for our day-to-day lives.

Recurring Themes in the Law

When we look at the content of the law, we will see some recurring themes we should pay attention to, such as God’s sovereignty, holiness, and grace; the shape of worship; and how seriously God takes sin. The law shows us that God cares about every aspect of our lives, our bodies, our attitudes toward our family members and neighbors, our celebrations. God is not just handing down random laws to trip up His people. When we read laws about what Israel could eat and what they must refrain from eating, we learn that God is holy and requires His people to live holy lives. God does not want them to be like the nations around them who did not know or worship God. He wanted His people to stand out, set apart for Him. When we read about what would make Israel unclean, we learn that God requires purification for His people, from the inside out. From their inward attitudes to their outward behavior, the Israelites were to be a people marked by holiness so all the nations would know they worshiped the one true God (Leviticus 20:26). The people knew this was impossible for them to achieve on their own, so they needed the symbolic substitute that helped them anticipate and long for the Messiah who would come to make all things new, reverse the curse of the Fall, and restore humanity to a right relationship with God.

Our Deliverer

Where Israel was bound by the law to keep and do it (Deuteronomy 4:6), we are bound by the law of Christ, which frees us from the demands of the law because Christ has fulfilled the law on our behalf. His sacrifice was what the Old Testament sacrificial system pointed to. We now come to God not through ritualistic sacrifice and cleansing but through faith in Christ. Through faith in Christ we are made holy and set apart for God, we receive forgiveness of our sins, and we are made clean. Neither Israel nor we can obey God perfectly. Israel looked forward to the Messiah to fulfill God’s promise to deliver and restore His people. We look back on what Christ has done to deliver us from the domain of darkness and to transfer us to the kingdom of His beloved Son (Colossians 1:13). For Israel and for us, the law points to Christ.