Are You the Salt of the Earth and Light of the World?

Without Christians individually and constitued as the church, our culture cannot be won to Christ,and the culture will sink into the depths of depravity. Salt is a preservative and enhances taste to food. How does the church act as salt to a putrifying world? Jesus is the Light of the World, and the church is the light as well. Just how do we let our light shine? How do we make a difference? Could it be that one is a nominal Christian and not a genuine Christian?