When Jesus took His disciples into the mountains, he taught them that they must become the salt of the Earth.  He likened His disciples to salt.  They were to the world what salt is in everyday life: salt season’s food; it hinders the spread of corruption; it creates thirst; it brings out the flavor.  Therefore, His followers add piquancy to human society, serve as a preservative, and make others long for the righteousness.

Before we continue this part of the discussion, allow me to give you a brief history of salt, in order that it may add some additional favor to this study.

Salt has been a precious commodity since ancient times.  It was often traded ounce for ounce for gold.  The early Chinese used coins made of salt for currency.  In many areas around the Mediterranean Sea, salt cakes were used as currency.  Several ancient cultures also levied taxes on salt.

The main sources of salt in ancient times were dry coastal areas, particularly those surrounding the Mediterranean Sea.  The earlier trade routes centered on Spain, Italy, Greece, and Egypt, and many of the first roads and caravan routes were established for the purpose of transporting salt.  A number of cities, including Genoa, Pisa, and Venice, developed as centers for the salt trade.

In the 1300’s, people near the coast of the North Sea in northern Europe began trading for salt, which they needed to preserve fish for shipping to inland markets.  Later, salt was obtained by boiling the brine from salt springs, and many cities and towns grew up near such springs throughout Europe.

The process of boiling brine to obtain salt required large supplies of wood for fuel, but this problem was partly solved in the 1700’s after coal began to be widely used.  England became the largest producer of salt in the world at that time, partly because of its abundant supply of coal.

Colonial America received most of its salt from England.  After the Revolutionary War in America (1775-1783), salt works were established along the Atlantic Coast for boiling seawater.  A salt industry also grew up near where the city of Syracuse, N.Y., now stands, after salt springs were discovered there.  The need to transport salt from Syracuse was one of the main reasons for the construction of the Erie Canal, completed in 1825.

Deep-drilling technology was introduced into salt production in the early 1800’s.  Most early wells were drilled to improve the quality of salt springs that were already being used in salt production and to locate new ones.  Production of salt from underground mines began in the mid-1800’s.

Drilling helped revolutionize knowledge of the earth’s layers.  This new knowledge led to increased exploration for salt, potash, and petroleum and salt exploration indirectly gave rise to such industries as the potash industry and the petroleum industry.

Today, the U.S. government is investigating the possibility of storing radioactive wastes in underground salt mines.  Salt mines have several characteristics that make them good sites for radioactive wastes.  For example, they have remained stable and dry for millions of years, and most salt mines occur in areas where earthquakes are extremely rare.  Salt also is capable of absorbing heat from surrounding objects, and it flows to seal up fractures that form in the walls.

This is a principle Jesus clearly understood and He wanted to make sure that His disciples understood it also in order that they too could teach it to the rest of the world.  Jesus told them that if the salt loses its flavor, how can its saltiness be restored.  There is no way to restore the true, natural taste.  Once it has lost its flavor, salt is good for nothing.  As salt preserves and brings out the best flavor of food, so believers should be the salt of the earth and affect others positively.  Jesus told his disciples that if they wanted to make a difference in the world, they would have to be different from the world.  God would hold them accountable to maintain their saltiness (that is, their usefulness).  We must be different if we want to make a difference.  We must be the salt of the earth.