Christians and the Old Testament laws

Do not suppose that I came to abolish the Law or the Prophets; I did not come to abolish them but to fulfill them. I tell you truly, until heaven and earth pass away, not the smallest letter or slightest stroke of the pen will pass away from the Law until everything is accomplished. Therefore, whoever sets aside one of the smallest of these commandments and teaches others to disregard them will be called the least in the kingdom of heaven, but whoever does them and teaches them will be called great in the kingdom of heaven. For I tell you that unless your righteousness goes far beyond that of the scribes and Pharisees, you will never enter the kingdom of heaven.
Matthew 5:17–20

God gave his ancient people the “Law and the Prophets” (another name for the Old Testament) to help them identify the Messiah and prepare for his coming. In the fullness of time, the Messiah came to accomplish what the Scriptures predicted. This did not abolish the authority of the Scriptures, but the role of the first testament changed when the One it pointed to arrived. Since Jesus’s coming, every Old Testament commandment must be filtered through what we might call a “fulfillment-in-Christ” grid. We do that by identifying the eternal principle behind the commandment and applying it to our circumstances.

How Jesus “fulfilled” the Law and the Prophets

Do not suppose that I came to abolish the Law or the Prophets; I did not come to abolish them but to fulfill them.
Matthew 5:17

Our world is driven by the desire to discover the truth about everything. We want to know what’s going on in the furtherest reaches of space, and we want to understand the smallest particles of the universe. And after all our research, are there things we can say are true? Yes. We call many of these truths “laws.” We have the law of gravity, the first and second laws of thermodynamics, and many others.

How to be Salt and Light

You are the salt of the earth, but if the salt becomes flavorless, how can it be made salty again? It is no longer good for anything except to be thrown out and trampled under people’s feet.

You are the light of the world. A city set on a hill cannot be hidden. Nor do people light a lamp and put it under a basket–they put it on the lamp stand so that it gives light to everyone in the house. In the same way, let your light shine before others so that they can see your good works and give glory to your Father in heaven.
Matthew 5:13-16

Jesus’s disciples were probably shocked to hear him describe them with such lofty titles as “salt of the earth” and “light of the world.” The men and women on the hillside were new believers. How could Jesus describe these often confused and perpetually fumbling followers as the salt of the earth and the light of the world?

Jesus could confidently describe his apprentices as salt and light because Jesus is the salt of the earth and the light of the world.

Salt of the Earth–Light of the World

You are the salt of the earth, but if the salt becomes flavorless, how can it be made salty again? It is no longer good for anything except to be thrown out and trampled under people’s feet.

You are the light of the world. A city set on a hill cannot be hidden. Nor do people light a lamp and put it under a basket–they put it on the lamp stand so that it gives light to everyone in the house. In the same way, let your light shine before others so that they can see your good works and give glory to your Father in heaven.
Matthew 5:13-16

Jesus begins the Sermon on the Mount with a dynamic list that describes his life and the life of his apprentices, and it doesn’t take long for the reader/listener to realize that Jesus is describing a life of activity and engagement. He mentions characteristics like showing mercy and being a peacemaker that are a call to participate in life in positive ways– showing compassion to the hurting, opposing injustice, confronting prejudice, standing for righteousness, seeking reconciliation between people in conflict with God or one another–this is how Jesus lived and how he wants his followers to live, but he says there will be a cost: persecution. Jesus then uses two familiar images to illustrate the impact his apprentices will have on the world around them: they will be salt and light.