Salt is the world's oldest known food additive. It plays a critical role in maintaining our health. Without enough salt in our body, muscles will not contract, blood will not circulate, food will not digest, and the heart will not beat. Salt is essential to life.

In the same way, Jesus' disciples have a vital role to play in influencing the world for God. Jesus continues to tell us, His disciples, who we are: We are the salt of the earth (v. 13). In other words, God's people are central to all that God is doing in the world. Through His disciples God wants to bless others: to bring to them the good news that their sins are forgiven; to help the poor; and to promote justice. One of our deepest human desires is to make a lasting difference in life. Here, Jesus says that His people make an impact on the widest possible scale: You are the salt of the earth.

Moreover, you are the light of the world (v. 14). Again we see the global dimension of this impact. Jesus goes on to stress the importance of His disciples having such an impact. Salt by its very nature is salty. A light naturally shines. If it does not, it is useless and is thrown out. Salt and light is what we are. Salt and light is what we must be.

Of course, by ″salt″ and ″light″ Jesus means our good deeds (v. 16). He will continue to teach about living righteously for the rest of the sermon. That means our lives, in conformity to God's will, are to be full of good deeds. Why? ″That they may . . . glorify your Father in heaven″ (v. 16). Yes, through our good deeds God desires to bless His world, but His ultimate purpose-in this and all things-is that He might receive praise and glory.

That is why we cannot be ″silent witnesses″. Nobody that our lives touch will ever turn and glorify the Father in heaven unless we tell them about Him. They will never appreciate that we have been merciful to them unless we testify of God's mercy to us. When we flavour and shine, and speak of the Father, however, the world will give Him honour and praise.