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. (Matthew 5:13)
We need to begin by pointing out that Jesus says that "you" are the salt. Jesus is our hope and the truth, but individual Christians (as well as the institution of the Church) have missionary calls.
But, what does salt represent? There is a debate about the meaning of salt and Christians have interpreted this image a variety of ways. Some say that salt brings a satisfying taste to bland food; thus, Christians are to bring taste to the world. Some have lumped all the interpretations together and tried to interpret a broad category. All the interpretations benefit the world in some way therefore they simply interpret this image to mean that Christians are to simply benefit the world, sort of like the United Way. All these interpretations could be right, but we can only be sure about one usage of salt in Jesus' day. Salt was used to preserve decaying food. The heart of this illustration is that Christians are to be a preserving force in their decaying city.
But this preserving salt metaphor means something regarding the nature of Christians as well as the nature of the city. The biblical view of the world is that it is decaying. This does not mean it is decaying as fast as it possibly can or that every aspect of our world is constantly decaying. However, the general and basic trajectory of our world is one of decay. It also means that the Church, individual Christians as well as the institution, are to be the preserving element for this decay. You and I are called to fix this problem! You and I are the medicine for this disease!
But, what does losing saltiness represent? Some have tried to say that losing your saltiness and being trampled upon means that you lose your salvation. We didn't earn our salvation (Jesus did) so we can't lose our salvation. Thus, losing our salvation can't be the meaning. We can't lose our salvation, but we can lose our missionary effectiveness and become useless missionaries. Salt really can't lose its saltiness but it can lose its taste or effectiveness if it is mixed with too much other stuff. If you mix in a bunch of sand into a bowl of salt it is going to become useless to prevent the decay in the meat. Here is what this means for us...we can love the world in the flesh and be like the world rather than distinct from it to the degree of losing our missionary effectiveness. You can mix so much of the world into your life that the distinctiveness of the salt loses its purpose. The Beatitudes are incredibly helpful to show us how to live distinct from the world. If we lose this distinction we lose our purpose. If the salt gets diluted, the mission is lost. We are to be missionaries, not monks, striving to preserve our decaying world. Our missionary strategy is to live so radically committed to Jesus that our lives are seen as beautifully distinct. Our distinction is to be a gospel lighthouse.
What area of your life is getting diluted? What worldliness do you need to repent of today? Pray that God would take you out of the monastery and use you as a missionary today!