'Salt' in the Bible

You are the salt of the earth; but if its taste goes from the salt, how will you make it salt again? it is then good for nothing but to be put out and crushed under foot by men.

Salt is good; but if the taste goes from it, how will you make it salt again? Have salt in yourselves, and be at peace one with another.

For salt is good, but if the taste goes from it, of what use is it?

Let your talk be with grace, mixed with salt, so that you may be able to give an answer to everyone.

Is a fig-tree able to give us olives, my brothers, or do we get figs from a vine, or sweet water from the salt sea?