I don't think I understood salt until I started cooking. How often do we think about the only rock that we eat? Salt was something I mindlessly added to food, almost on reflex when it would hit the table. Now, I can recognize when I forgot salt, or left a dish under seasoned. Something is definitely missing. It is hard to explain unless you see or taste it for yourself. Unfortunately [or fortunately] Al Gore has yet to add taste-o-net functions to his invention of the internet so I hope you try it, on purpose sometime. As my favorite celebrity chef says, "Salt, you might not know it when it is there but you'll definitely miss it when it is gone."
That natural experience of cooking has added a whole new reality to Matthew 5:13 You are the salt of the earth. But if salt loses its taste, with what can it be seasoned? It is no longer good for anything but to be thrown out and trampled underfoot.
What does salt do in cooking? It enhances flavors and raises awareness of what is going on in the food itself. Aspects to the food: brightness, savor, smokeyness, and sweetness might go untasted unless salt is there to draw them out. So we are to be salt.
Particularly in our time, we are to draw attention to the greater dimensions of life. We must awaken others to the spiritual dimension of life that would otherwise go unnoticed and hidden. We must preserve against the death of desire.
Just as a child who has only eaten candy bars would not know the sweetness and goodness of a pork loin, the world around us is loosing its appetite for the Divine. It is a natural appetite, but one that we can diminish to the point of loss. We Christians can reawaken a desire for the infinite, for God, by living Christian lives.
Sometimes, when a dinner is off, flat, or tasteless, it doesn't need fancy additives or exotic ingredients, it needs simple salt. Our culture doesn't need heroic acts but we do need simple Christian faithfulness. We don't need amazing miracles but we do need simple Christian virtues. This simple living will do to transform our culture than any politician or referendum- it is the power of people, the power of the saints.