Law is a very important part of several covenants documented in the Bible. The Old Covenant was given by God through Moses to the ancient Israelites. It was a national covenant and only Jews were subject to it. More than 600 commandments comprised the law under this covenant!
Christians not "under" law
The writers of the New Testament books of the Bible made it very clear that the Old Covenant has fulfilled its purpose and no one is under it today. Instead, Christians are subject to the New Covenant. The New Covenant has only one law and, as odd as it may sound, the apostle Paul teaches us that Christians are not even “under” the one law that we have!
For sin shall not have dominion over you, for you are not under law but under grace. (Rom. 6:14 NKJV)
A very important principle for Christians to understand is that they are not under law. To be "under" law means that people are subject to the authority of the law to judge and condemn anyone who breaks it. The New Testament portrays Christians as being under grace and therefore, law has no such power over us. Because of what Jesus did for us we benefit from God’s generosity (grace) and are not subject to the penalties of breaking the law.
1 So now anyone who is in Christ Jesus is not judged guilty. 2 That is because in Christ Jesus the law of the Spirit that brings life made you free. It made you free from the law that brings sin and death. 3 The law was without power because it was made weak by our sinful selves. But God did what the law could not do: He sent his own Son to earth with the same human life that everyone else uses for sin. God sent him to be an offering to pay for sin. So God used a human life to destroy sin. 4 He did this so that we could be right just as the law said we must be. Now we don't live following our sinful selves. We live following the Spirit. (Rom 8:1-4 ERV)
Yet, there must be law of some kind or it would not be possible for the Christian to sin. Where there is no law there is nothing to disobey (Rom 4:15).
There is a law for Christians
There is one law for those under the New Covenant (as opposed to 600+ under the Old Covenant) and is described in a few different ways in the New Testament writings.
- Law of Christ (Gal 6:2, 1 Cor 9:21)
- Law of God (Rom 7:22, 1 Cor 9:21)
- Law of Liberty (Jam 1:25, 2:12)
- The Royal Law (Jam 2:8)
- Law of Faith (Rom 3:27)
So, what is this law exactly? Let’s let the Bible speak for itself.
If you really fulfill the royal law according to the Scripture, "You shall love your neighbor as yourself," you are doing well. (Jas. 2:8 ESV)
That’s it, the only law of the New Covenant is love. The concept of love is the most fundamental principle of the Bible. Consider this sampling of passages.
Carry each other's burdens, and in this way you will fulfill the law of Christ. (Gal. 6:2 NIV)
Therefore, as we have opportunity, let us do good to all people, especially to those who belong to the family of believers. (Gal. 6:10 NIV)
Anyone who loves their brother and sister lives in the light, and there is nothing in them to make them stumble. (1 Jn. 2:10 NIV)
This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not God's child, nor is anyone who does not love their brother and sister. (1 Jn. 3:10 NIV)
And this is his command: to believe in the name of his Son, Jesus Christ, and to love one another as he commanded us. (1 Jn. 3:23 NIV)
Jesus was once asked,
36 "Teacher, which is the great commandment in the law?" 37 Jesus said to him, "`You shall love the LORD your God with all your heart, with all your soul, and with all your mind.' 38 "This is the first and great commandment. 39 "And the second is like it:`You shall love your neighbor as yourself.' (Matt. 22:36-39 NKJV)
From His answer we learn that love is the very essence of what it means to be a follower of God and a keeper of the law.
The only thing that counts...
If any doubt remains about this “law,” Paul’s very direct statement should help clarify that love is the Christian’s law.
For in Christ Jesus neither circumcision nor uncircumcision has any value. The only thing that counts is faith expressing itself through love. Gal. 5:6 NIV
The law of Christ
Someone may ask, “What about all the commandments in the New Testament? Aren’t those part of the law of the New Covenant?”
The Law of Christ is that we love God and love our fellow man. The commandments God has given us in the New Testament aren't meant to represent a new law that is merely a replacement for the Old Covenant law, but instead are given to teach us how to love one another. If we instinctively knew how to love each other, God would not have needed to give us commands and directives. For example, we have commandments against adultery because adultery hurts not only our spouse, but ourselves and everyone else who loves us. We do not show love by committing adultery. We have commandments against stealing because theft hurts the one who is stolen from. If we love people, we will not steal from them. God's commandments are not arbitrary rules for us to follow as a test to see who can be obedient enough to merit Heaven. In reality, the commandments of the New Covenant serve as instructions which teach us how to fulfill the one law - to love God and one another.
8 Owe no one anything except to love one another, for he who loves another has fulfilled the law. 9 For the commandments, "You shall not commit adultery," "You shall not murder," "You shall not steal," "You shall not bear false witness," "You shall not covet," and if there is any other commandment, are all summed up in this saying, namely, "You shall love your neighbor as yourself." 10 Love does no harm to a neighbor; therefore love is the fulfillment of the law. (Rom. 13:8-10 NKJV)
The commandments in the New Testament writings are the things people do when they love God and love one another! We don’t obey the commandments in order to stay saved, but because we are saved. A good analogy to help understand this idea is to consider a dog. A dog does not bark, chase his tail or fetch in order to be a dog. No, a dog does these things because he is a dog. It's just a part of his nature; he doesn't focus and fixate on doing "dog things", he just does them. If you are a dog, these are the things you do - you can't do otherwise.
Likewise, a Christian shouldn't have to focus or fixate on obeying the commandments of God, we just do them because that is now who we are. As God transforms us to become more like Him our nature is slowly changed. We love other people (aka obey the commandments) because it's part of our new nature. It's automatic and we can't do otherwise. We love others and do "God things" because we are His children, not in order to be His children. The commandments of the New Covenant describe the actions done by people who are filled with love.
We sin when we fail to love as we should. The law we break when we sin is the law of love. Nevertheless we will not be condemned by breaking the law of Christ as long as we walk in the Spirit (Rom 8:4), which is another way of saying that we remain faithful and penitent. On the day of judgement, the verdict of the faithful will be, "Guilty! But no penalty." There will be no penalty because we are "under" grace, not law.