Salt and light are important ingredients to our everyday living. A little salt makes a big change in the way food tastes and a little light transforms a dark room. These ordinary everyday things are very powerful change agents.
When Jesus called his followers to be salt and light (Matthew 5:13-16) he was affirming a familiar theme in scripture. God’s first command to the first human beings on earth was “to work it and take care of it.”(Genesis 2:15). Then, even after the fall of humanity when most have rejected God, he reiterated the call to Noah (Genesis 9:1-3). Then when the people of Israel are in exile in Babylon he calls them to “seek the peace and prosperity of the city to which I have carried you into exile” (Jeremiah 29:7).
Similarly, in the New Testament Peter encourages Christians to see how they can impact those who don’t believe by the way they live their lives (1 Peter 2:12).