Mat 5:13 You are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.

Alternative: You are the salt of the earth; but if salt is insipid, how shall it be seasons? It is no longer good for anything except to be thrown out and trodden under people's feet.

For a long time, this passage confused me because I wondered how salt could lose its taste. Some Biblical scholars like to talk about saltlike fertilizers and how these might lose there effectiveness. I think this is a stretch. However, the translation confuses the message here. The Greek moraino is translated here as "lost is its taste" but its normal meaning is "to act foolishly." Another common meaning of salt is "wit," so Christ is saying fairly clearly that people are naturally witty, having common sense, but that we can become foolish. Only in this passage is moraino ever translated as "to make tasteless," (which I guess could make sense in the sense that foolish people make tasteless jokes.)

To understand the deeper meaning here, we have to understand the importance of salt in Christ time. It wasn't only a seasoning, but it was also used as pay and, more importantly, as a preservative. Remember, there was no refrigeration in this period and no other preservatives other than spices, of which salt was the only plentify one. This is what made if valuable enough to be used as pay. Real salt did not lose its saltiness. It was stable enough to be used as a currency. Our word "salary" comes from the Latin for salt.

So, when Christ says the his people are the "salt of the earth," he is saying that they are the valuable, those he describes in the Beatitudes preserve what is valuable. As salt preserves food, people preserve valuable ideas. In one sense, he is referring to the Jewish people then (and Christians today) as the preservers of the Bible.

Salt may not lose its saltiness, but good, valuable people can become foolish. Also in ancient Greek, there was a phrase (ean to halas môranthêi ) which means to become insipid and combines the terms for salt (halas) and foolish (môranthêi) into "fool's salt" the same way we would call false gold "fool's gold." So Christ is saying here, that good people can make themselves into fools. People can be foolish when they fail to preserve what is valuable.

Another way something salty can become "foolish" is for a preserved product to go bad. In calling good people "the salt of the eath," Christ is also saying that we have been preserved or saved. However, we can still go bad by become foolish and insipid. When a salted product goes bad, it no longer tastes salty, it tastes, well, bad. A little taint goes a long way.

What happens to tainted products? Or what happens when we discover that what we thought was salt proves to be "fool's salt." Well, these bad products can't be fixed by adding more salt. They are caste out. "Trodden under foot" in Greek is metaphor for being spurned or rejected.

"Salt" is from halas (halas) ( see hals for more detail), which means "salt," "salt-rock," "brine," and is a metaphor for "sales" and "wit."

"Lost his savour" is from môrainô (moraino), which means "to play a fool," "to act foolishly," "to be silling," and "to be insipid."

"Good" is from ischuô (ischuo), which means "to be strong in body," "to be powerful," "to prevail," and "to be worth."

"Trodden" is from katapateô (katapateo), which means "trample," and "trample down." It is also a metaphor for treating someone rudely or spurning them, treating them with neglect.