“You are the salt of the earth, but if salt has lost its taste, how shall its saltiness be restored? 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, but on a stand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.” -Matthew 5:13–16
Jesus uses the analogy of salt and light to refer to the life of his followers in this world. Christians are the salt of the earth. Salt during Jesus’ time period was very important. It was used on meat to slow down the process of petrification. In a time where you couldn’t find a refrigerator or freezer to save your life; salt was a high commodity. It was also used in the same way you and I use it today; to flavor food. I happen to love salt and use it on just about everything.
The third way we use salt is to melt ice and help traction. This is not the main function of high quality salt. I would not take the sea salt from our dinner table and go and sprinkle it on our driveway. I would use something cheaper and worse in quality for that task.
Christians are also the light of the world. Cities in that time period were set many times on white lime stone. It would make the city easy to see from a distance. The large number of people would also make the city seen from a distance by keeping their lamps lit at night. A city set on a hill cannot be hidden.
Jesus tells us his followers are both the salt and the light of the world. He commands us in verse 16 to ”let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.” So what are these good works he wants us to do? They are the kingdom principles, the beatitudes from verses 2–12. We are not the light of the world in the sense that there is goodness in ourselves worth emanating. We are the light of the world in the sense that there is perfection in Jesus worth reflecting. We reflect the light of God by having attitudes of true being; or the written beatitudes. Jesus calls us to reflect him while living in his world. And we can not begin to do that unless our hearts have been created new through the gospel of free grace. We want the world to give glory to your Father, who is in heaven and not to absorb glory for ourselves.