'Saltness' in the Bible

"*You* are the salt of the earth; but if salt has become tasteless, in what way can it regain its saltness? It is no longer good for anything but to be thrown away and trodden on by the passers by.

Salt is a good thing, but if the salt should become tasteless, what will you use to give it saltness? Have salt within you and live at peace with one another."