Matthew 5:13-20

These verses teach us, in the first place, the character which true Christians must support and maintain in the world.

The Lord Jesus tells us that true Christians are to be in the world like “salt.” “Ye are the salt of the earth.” Now salt has a peculiar taste of its own, utterly unlike anything else. When mingled with other substances it preserves them from corruption; it imparts a portion of its taste to everything it is mixed with. It is useful so long as it preserves its savour, but no longer. Are we true Christians? Then let us see here our office and our duties!

The Lord Jesus tells us that true Christians are to be in the world like light. “Ye are the light of the world.” Now it is the property of light to be utterly distinct from darkness. The least spark in a dark room can be seen at once. Of all things created, light is the most useful: it fertilizes; it guides; it cheers. It was the first thing called into being. (Gen. 1:3) Without it the world would be a gloomy blank. Are we true Christians? Then behold again our position and its responsibility!

Surely, if words mean anything, we are meant to learn from these two figures that there must be something marked, distinct, and peculiar about our character, if we are true Christians. It will never do to idle through life, thinking and living like others, if we mean to be owned by Christ as His people. Have we grace? Then it must be seen. Have we the Spirit? Then there must be fruit. Have we any saving religion? Then there must be a difference of habits, tastes, and turn of mind, between us and those who think only of the world. It is perfectly clear that true Christianity is something more than being baptized and going to church. “Salt” and “ light” evidently imply peculiarity both of heart and life, of faith and practice. We must dare to be singular and unlike the world, if we mean to be saved.

These verses teach us, in the second place, the relation between Christ’s teaching and that of the Old Testament.

This is a point of great importance, and one about which great errors prevail. Our Lord clears up the point in one striking sentence: He says, “Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.” These are remarkable words. They were deeply important when spoken, as satisfying the natural anxiety of the Jews on the point; they will be deeply important as long as the world stands, as a testimony that the religion of the Old and New Testaments is one harmonious whole.

The Lord Jesus came to fulfill the predictions of the prophets, who had long foretold that a Saviour would one day appear. He came to fulfill the ceremonial law, by becoming the great Sacrifice for sin, to which all the Mosaic offerings had ever pointed: He came to fulfill the moral law, by yielding to it a perfect obedience, which we could never have yielded, and by paying the penalty for our breach of it with His atoning blood, which we could never have paid. In all these ways He exalted the law of God, and made its importance more evident even than it had been before. In a word, “He magnified the law and made it honourable.” (Isa. 42:21)

There are deep lessons of wisdom to be learned from these words of our Lord about “the law and the prophets.” Let us consider them well, and lay them up in our hearts.

For one thing, let us beware of despising the Old Testament, under any pretence whatever. Let us never listen to those who bid us throw it aside as an obsolete, antiquated, useless book. The religion of the Old Testament is the germ of Christianity. The Old Testament is the Gospel in the bud; the New Testament is the Gospel in full flower. The Old Testament is the Gospel in the blade; the New Testament is the Gospel in full ear. The saints in the Old Testament saw many things through a glass darkly; but they all looked by faith to the same Saviour, and were led by the same Spirit as ourselves. These are no light matters. Much infidelity begins with an ignorant contempt of the Old Testament.

For another thing, let us beware of despising the law of the Ten Commandments. Let us not suppose for a moment that it is set aside by the Gospel, or that Christians have nothing to do with it. The coming of Christ did not alter the position of the Ten Commandments one hair’s breadth. If anything, it exalted and raised their authority. (Rom. 3:31) The law of the Ten Commandments is God’s eternal measure of right and wrong. By it is the knowledge of sin; by it the Spirit shows men their need of Christ, and drives them to Him: to it Christ refers His people as their rule and guide for holy living. In its right place it is just as important as “the glorious Gospel.” It cannot save us: we cannot be justified by it; but never, never let us despise it. It is a symptom of an ignorant ministry, and an unhealthy state of religion, when the law is lightly esteemed. The true Christian “delights in the law of God.” (Rom. 7:22)

In the last place, let us beware of supposing that the Gospel has lowered the standard of personal holiness, and that the Christian is not intended to be as strict and particular about his daily life as the Jew. This is an immense mistake, but one that is unhappily very common. So far from this being the case, the sanctification of the New Testament saint ought to exceed that of him who has nothing but the Old Testament for his guide. The more light we have, the more we ought to love God: the more clearly we see our own complete and full forgiveness in Christ, the more heartily ought we to work for His glory. We know what it cost to redeem us far better than the Old Testament saints did. We have read what happened in Gethsemane and on Calvary, and they only saw it dimly and indistinctly as a thing yet to come. May we never forget our obligations! The Christian who is content with a low standard of personal holiness has got much to learn.