You are the salt of the earth: but if the salt have lost his flavor, with which shall it be salted? it is thereafter good for nothing…
Our Lord assured his disciples that very bad treatment in this life might only be the prelude to eternal happiness. He is in the position of a general who is launching his men on an enterprise which will try them to the utmost. So he not only affirms that they will be rewarded, but reminds them how much depends on them. If you faint, what hope is there for the world? He speaks of their relation to the world under two figures - salt and light.
I. Salt was often used as a symbol of anything, like itself, pungent. Wit was so called, and in Christian times a gracious tone in conversation; in each case because of their power of redeeming from insipidity. But salt is used to preserve from corruption; and though the figure which represents society as tending to rot and dissolve is a strong one, any one who knows the facts knows how thoroughly appropriate it was. Nor can it be said to be inapplicable to society or family life now, though Christianity has acted so far like salt that corruption is not so flagrantly obtrusive. But the point chiefly emphasized is that they were the salt. They were not to expect to get good so much as to do good. It is their calling to counterwork the corruption that is in the world. All those things that tend to the lowering of spiritual life are the objects on which they are to act, and if instead of this they yield to them, it is because the salt has lost its savour. If the very persons who are appointed and equipped to carry with them a health-giving influence are themselves prostrated by the evil infection, if disinfectants carry disease-germs, what shall avail us? "If the salt have lost its savour, wherewith shall it be salted? It is good for nothing," says our Lord, "but to be cast out, and trodden under foot of men." This also is a strong, severe figure. Plainly we are intended to infer that nothing is more contemptible than a Christian who does nothing to stay corruption. He is a soldier who wears the uniform of his regiment, but leaves the fighting to others; a physician who declines to visit the sick. It is of the very essence of the Christian that he makes some impression on the world. The terms of Christ's call are, "I have chosen you, and placed you, that you might bring forth fruit." Observe that this figure applies especially to beginnings of evil, and to our treatment of the young. Salt can prevent corruption; it cannot cure it. Consider to what the smallest germ of sin in a child may grow; to what extent our life may become corrupt if we neglect to keep the salt of Christian principle.
II. Another danger threatens the disciples of Christ. While some will give up Christian principle altogether when they find how seriously it brings them into antagonism with the world, others will try to hide it. They will continue Christians, but secretly. It is this timorous evasion of opportunities of confessing Christ that he aims at in the figure, "Ye are the light of the world." In this figure several things are implied, as:
(1) that Christians are set for the illuminating of the world;
(2) that what illuminates must itself be visible;
(3) that it is as natural to genuine Christian principle to become visible as it is for light to shine.
1. Christians are set for the illuminating of the world. Our Lord kindled the few men who accepted him as the Light of the world, and they in turn kindled others. He has trusted himself with his followers. He has left it to us to maintain the knowledge of him on the earth, and to hand on the light which all men need. Christians were not to retire and hide themselves, satisfied if they could keep their own souls alive. They were to enter into all the innocent relationships and engagements of life, and so use them as to show their light. All our connections with the world are candlesticks, from which the light may advantageously shine. Persecution itself is one. "Truth, like a torch, the more it's shook it shines." The parental relation is another candlestick. Natural talent may set a man on such an eminence that his light is shed over the land; but all men have some stand from which they can shine, if it is in them to shine. Not the candlestick makes so much difference as the light you put in it. Does any say, "How can I shine - a dull, torpid mass?" Yet not so torpid probably as never to try to influence your fellows in some way. And the dullest body may be a good reflector of light shed. on it. The Christian's is not a self-kindled light.
2. The lesson more directly taught is, that whatever illuminates must itself be visible. If your conduct is to teach a better way to men, your conduct must be seen. Therefore are works here emphasized. Men cannot see your fine ideas, your noble purposes, your holy aspirations. Your thoughts about Christ, your faith in him, your tenderness of heart towards him, are as the oil in the lighthouse lamp. If no light is shown, shipwrecks will not be prevented. So it will not avail to prevent moral wrecks that you have felt anxious, devised ways of aiding, if you have done nothing. The man who is content to save his own soul, and is afraid to interfere with the wickedness around him, is not even saving his own soul. To the light hid under a bushel, or under a bed, one of two things will happen - it will either go out altogether, choked for want of air, or it will burn through its covering and find surprising expression for itself. For:
3. It is of the essence of Christian character to shine, to become visible. There is a kind of Christianity which burns high or low according to the company it is in. But the fact that it can be thus artificially manipulated, like a gas-jet, shows it is an artificial, and not a genuine, Christianity. If you are a Christian you have a law which covers your whole life, and a new spirit within you. Can a man have new fresh blood in his veins and that not show itself"? Just as little can a man have the joy of Christ's love and the reviving energy of his Spirit in his heart, and these not be seen in his demeanour. This witnessing for Christ is not an optional matter. "The good tree will show the good fruit. It cannot go on bearing the old bad fruit out of modesty or a pretended shrinking from ostentation; it must reveal the righteousness of God within by the righteousness of God without, else it is a mockery." The practical object our Lord has in view is declared in the words, "Let your light thus shine before men, that they may see your good works, and glorify your Father which is in heaven." How does this agree with the injunction to hide your good works - not to let your right hand know what your left hand does? In this way. We are to avoid the two extremes of ostentation and timorous shrinking in our conduct; to abandon all affectation, all false delicacy, all pretended modesty and real fear, and live out with simplicity and fearlessness the Christian principle we know and accept. Observe that when our Lord specifies "good works" he does not exclude good words. Often it is a good work to speak the word wanted. And though it is often one of the most difficult of duties, it is certain that we are guilty if we neglect this mode of confessing Christ before men. To be backward in this is a sign that our own light is burning low. - D.
Parallel VersesKJV: Ye 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.