'Salt' 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."

"Salt is good: but if even the salt has become tasteless, what will you use to season it?

Let your language be always seasoned with the salt of grace, so that you may know how to give every man a fitting answer.

Can a fig-tree, my brethren, yield olives, or a vine yield figs? No; and neither can salt water yield sweet.