Salt preserves, purifies and seasons and when scattered on an icy road provides traction. In whatever the situation it is being used, it has an influence in preserving the good and changing the bad.  The Lord Jesus described Believers as "the salt of the earth" (Mat 5:13). In the environment we live and work we may feel we have very little influence, but we equally know that the influence of even very small amounts of salt are soon obvious! It is our opportunity as Christians to influence those around us. The silent or vocal witness of a believer does make a difference. Who will we influence for good today?

In Scripture, mankind is said to be entirely corrupt (Rom 3:10). To some extent this corruption  is counteracted by the active presence of Christians, and the work of the Holy Spirit bringing conviction of sin. For example, we're told that our speech should be seasoned with salt (Col 4:6), so that our words "purify" our listeners and hopefully also make them thirsty for the living water which alone can satisfy them.

The metaphor of salt representing the effect of a Christian involves Being, rather than doing. We are to be like salt as we shop, or work, or bank, or even cut the lawn. Good salt just naturally restricts further corruption, it creates thirst, seasons food, cleanses wounds, and maintains balance. All these things should be true of the Christian Believer, and our manner of life should “create thirst” in those who are in the world, without Christ, and without hope. Looking back to my Teenage years, that is how I (EMO) probably came to the Lord through wanting what other young folk had who had become Christians. We should live our lives in such a way that people will want what we have, or better still, want Who we have! We should generate a desire in people’s hearts and minds for something better. There is a thirsty world out there, and we need to attract them to the living water!  We are not to be cloistered as monks, but our characters and lives are to be on open display.

The apostles could be described as the salt of the whole earth, for they were to go into all the world to preach the gospel. They might have been discouraged that there was so few of them for this mighty task, and they were so weak. But as we know, one small handful of salt can go a very, very, long way.

Let's just reflect on the last part of this verse, Mat 5:13. Suppose the salt has lost its savour - that is, it has become tasteless, or has lost its preserving properties. This probably won't literally be the case in many countries these days, because pure salt is a chemical compound of one atom of sodium and one of chlorine. However when put upon the roads to deice them it is usually mixed with sand, gravel, etc. When the salt gets washed away, you are simply left with sand or gravel etc, and that is just trodden under foot of men. A preacher, or private Christian, who has lost a living relationship with the life of Christ, and the witness of His Spirit,  may be likened to this salt. He may have the sparks and glittering particles of true wisdom, but no longer have its power or comfort. What could have happened then is that the salt has lost its savour, and divine power is absent from our lives because the Holy Spirit is grieved or quenched. For example, the Galatians had begun in the Spirit, but sought completion by the flesh (Gal_3:3). Believers who return to the law can have but little testimony in a religious world dominated by law. Such salt is fit only to be cast out of such a life, for those who sow to the flesh shall of the flesh reap corruption (Gal_6:8).

The disciple then has this great function—to be the salt of the earth  - by living out the terms of discipleship listed in the Scriptures, by imitating as far as he can with God's help, the life of Christ. If the Christian fails to exhibit this spiritual reality, men will tread his testimony under their feet. The world has only contempt for an undedicated believer.

Vernon McGee comments: "The Scots translate "savour" by the more expressive word "tang". "If the salt has lost its tang." The problem today is that many of those in fellowship in a church have not only lost their tang as salt, but as pepper they have lost their pep also. We have very few salt and pepper Christians in our day. Now salt doesn't keep fermentation and that type of thing from taking place, but it will arrest it. We ought to be the salt in the earth and have an influence for good in the world".

Who wants to be a good-for-nothing Christian? Paul was concerned that he could be one (1 Cor 9:27), or that others might be one—“saved so as by fire” (1 Cor 3:15). God has many purposes for His children, and these include vibrant lives that testify daily to the Lord’s grace. We need to aspire to be good-for-everything Christians.