When taking the opportunity to portray true Christian identity, Jesus used salt and light in Matthew 5:13-16.  Through these two metaphors, He painted a picture of the expected nature of a genuine believer.  In so doing, Jesus adhered to His original representation of salvation in the beatitudes (verses 3-12) and invoked the association with the Word of God (verses 17-20).

Salt can and will retard corruption and enhance taste if it retains its fundamental characteristic of saltiness.  Salt without saltiness is worthless.  Jesus said, “Ye are salt.”  Specific people are salt, those who have saltiness.  Very often scripture portrays unbelievers as worthless.  They aren’t functioning according to the image of God in which He created man.  They are like the branches of John 15, bearing no fruit and so thrown into the fire.  They are worthless branches.

At the time Jesus spoke, salt was of great value.  Roman soldiers were paid in salt, which pay meant they operated in a competent way.  They were worth their salt.

The blessed man, one with the ultimate fulfillment of true salvation and receives the kingdom of heaven, is persecuted for righteousness’ sake.  The righteousness stands up to and contrasts and conflicts with evil.  This is being salt.  A true believer’s righteousness will clash with false doctrine and practice.  He’s not salt if he doesn’t.

The standard for the genuine believer’s conflict to retard corruption is scripture.  The true believer lives according to and propagates the Word of God.   Scripture manifests the nature of God.  To take on the nature of God, the true believer retards decay by detecting and correcting false doctrine and practice according to the Word of God.

The nature of the world conflicts with the nature of God.  This results in persecution.  Rather than succumb to the pressure of that persecution, the true believer will continue as salt, retarding the corruption.  This doesn’t occur by destroying the law, but by fulfilling it, every jot and tittle (verses 17-18).  The genuine believe retains saltiness in the face of persecution.  It’s his nature and that won’t change with opposition, a characteristic Jesus front loads in His description of salvation.

The opposition to darkness isn’t selective.  It’s every jot and tittle.  As Jesus continues, it is teaching not just the “essentials,” but even the least of God’s commandments.  The righteousness of true Christianity supercedes the righteousness of the Pharisees.  It doesn’t dumb down righteousness to a standard that can be kept by men.  This is the salt losing its saltiness and becoming worthless.

Churches today are becoming worthless at retarding the unrighteousness of the world, because they are not standing up for righteousness.  They stand up for selective or relative righteousness, not every jot or tittle. They are ashamed of many points of scripture and refuse to be salt where Christianity most clashes with the world.  They are not worth their salt.