It doesn’t take long to find a pastor or person teaching that the Ten Commandments or “Law” has no place today in the life of a disciple of Christ. There are some who actually go so far as to claim that the early church put the Mosaic Law on the shelf, a relic of a time gone by. Still, others say that the Law is confusing, indefensible, and irrelevant. While certainly challenging, the Law actually serves as a type of compass and map to do three things: First, it reveals who God is, second, it exposes who we are, and, third, it reminds us of how we are to live every day. 

The Law reveals who God is

The Law given to Moses at Sinai serves as a reflection of the character of God.  Certainly, standards such as “do not kill” were around before the Mosaic Law.  But these standards were new in the sense that they were now both specific and authoritative – coming from God Himself. Prior to the giving of the Law to the Jewish people, the conscience served as an unwritten law on the hearts of all people (see Romans 2:14-16). However, there was no way to connect a specific standard to God directly until that moment in time in which the Law was given from God to Moses.  A person could have pointed out the rationale as to why it is wrong to murder, but it was now clear that murder was wrong because God says it is wrong.   Today, this standard is ubiquitous among all cultures in our world.  It is easy to see the ethic of God’s Law now embedded within governmental laws throughout the world.  Everywhere you turn there is an expression of Divine design, a hint of orderly structure in civil law.  The ethic revealed in the Law of God was designed to regulate society as well as to provide external punishments for people who refuse to follow these standards.

Given the global impact of Christianity, there is a discernible Judeo-Christian ethic that has been incorporated into societal standards for which civil laws are generally founded. The role of this “first use of the Law” explains the moral imprint on civic law.  For example, Bill is pulled over by a police officer for driving 45 M.P.H. in a 25 M.P.H. school zone.  Bill receives a large fine due to his disregard for the law, a law designed to protect the life of kids as they travel to and from school.  Bill puts others in danger because we value human life.  Bill did not follow the rule and now the penalty is designed to make him aware that the law must be obeyed.  

The Law exposes who we are

The second use of the law is internal and designed to reveal to humanity our sinful condition when do not act as we should.  In other words, the second use of the Law is intended to reveal that we are law-breakers.  For example, Bill believes he is a good person. Bill also vaguely assumes that there is a God and that he is righteous enough to stand before Him one day. However, Bill reads the ninth commandment, “Do not lie,” (Exodus 20:16) and is struck by how often he has lied and who he has lied to. The truth of God’s Law applied to Bill’s life reveals to him that he is unrighteous.  It also uncovers how little Bill really cares for God – the One whose command Bill is violating. This leads Bill to question whether or not he is truly “good.”  The standard of the Law when applied to the life of Bill, leads him realize that he is not as good as he once thought.  The Law exposed the heart of Bill.  This would be an example of the second use of the Law, the Law’s relationship to the non-Christian in revealing his or her sin. 

Paul speaks of this “second use” when he writes: 

“Now we know that the law is good, if one uses it lawfully, ⁹ understanding this, that the law is not laid down for the just but for the lawless and disobedient, for the ungodly and sinners, for the unholy and profane, for those who strike their fathers and mothers, for murderers, ¹⁰ the sexually immoral, men who practice homosexuality, enslavers, liars, perjurers, and whatever else is contrary to sound doctrine, ¹¹ in accordance with the gospel of the glory of the blessed God with which I have been entrusted.”

Notice how Paul urges Timothy to apply the Law to the lives of people in order to reveal their spiritual condition?  Like an X-Ray machine reveals the unseen qualities in a bone, so the Law reveals the condition of the heart before a Holy God. The “second use” of the Law serves as the primary tool in which the Holy Spirit reveals that we have all sinned, we have committed cosmic treason against our Maker.

The Law reminds us of how we are to live

The third way in which the Law is used is directed at those who have trusted in Christ as payment for their sin.

In this category, God’s Law in the Old Testament serves as a type of guide, showing us how to live. The Law does this through serving as a continual reminder of both God’s holy character (expressed in the Old Testament Law) as well as the atoning work of Christ to fulfill the Law on our behalf (New Testament).  When reminded of our need for forgiveness and then the forgiveness obtained by Christ, the believer is aroused to greater obedience that flows from a grateful heart.  The obedience of the disciple does not become the basis for his or her salvation but a response to/for their salvation. The believer is motivated (through the third use of the Law) to live a Gospel-fueled life because his or her sin has been forgiven. We can see new Testament writers use this third law in a variety of ways. For example, Paul tells children to obey their parents (the fifth commandment) “in the Lord” (Ephesians 6:1-2). When discussing the role of the Holy Spirit how a disciple of Jesus is to treat another person to obey the whole law, Paul cites Leviticus 19:18: “Love your neighbor as yourself.”  Paul uses the guidance of Proverbs 25:21-22 to recommend a course of action for interacting with an enemy.  In each example, Paul’s teaching is rooted in the Old Testament Law – the thing we now desire to obey given Christ’s gracious provision of salvation expressed in the New Testament. We don’t want to obey the Law to earn anything, we want to obey the Law because we want to be “imitators [lit. “mimics”] of God” (Ephesians 5:1).

Let’s apply how the “third use” of the law works in the life of Bill. Bill is now a Christian and is planning on doing his taxes in the afternoon. During Bill’s devotions, he reads the 9th Commandment –  “Do not lie” and meditates on its many implications to his life.  Bill then realizes the implications for his taxes. Bill was not planning on cutting corners to begin with and now he asks the Holy Spirit to help him to be honest and for the Lord to use that honesty in completing his taxes with integrity.  Bill does this out of gratitude for what Christ has done for him on the cross and the freedom he now has to enjoy Christ more than he loves his money.  The work of Christ on Bill’s behalf has created a priority in his life to live for Christ, from which he is regularly reminded of through the third use of the Law.

People who want to do away with or manipulate the Law to suit their own desires are unwittingly severing a key joy-inducing mechanism that celebrates the good news that Jesus provides. To relegate the Law in merely being applicable to the Old Testament Covenant, not only betrays the three uses of the Law by New Testament writers, but this view actually abandons the very character of God revealed in the Law as well as the various pictures of the work of Christ flowing from the sacrificial system and prophetic writings.

Jesus Himself told us when the Law will no longer be valid: “For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished”  (Matthew 5:18).  

While there will always be new and uninformed Christians who still need to grow in understanding of how the Law and the entire Old Testament relate to the life of the disciple today, there is no excuse for a misinformed pastor to teach that the Old Testament has no value today. It is obvious that the Law is essential for us today.  It is not merely that we want the entire message of the Old Testament, but that we need it to be healthy, fully-formed disciples of Jesus today.