*Ye* are the salt of the earth; but if the salt have become insipid, wherewith shall it be salted? It is no longer fit for anything but to be cast out and to be trodden under foot by men.
Commento di questo versetto
I have enough material. Drafting the commentary now.
The Place the Lord Assigns His Own
In the opening of the Sermon on the Mount, the Lord has just sketched the character of those who belong to the kingdom — the poor in spirit, the mourners, the meek, the hungry after righteousness, the merciful, the pure, the peacemakers, the persecuted. Then, turning from what they are to where they stand, He says: "Ye are the salt of the earth."
William Kelly devoted an entire paper to this single verse, and explains why it follows exactly where it does:
William KellyThe Lord had laid down in vers. 5-9 the distinctive moral qualities suited to the kingdom of the heavens, with the supplemental blessednesses in sufferings (10-12). He now proceeds to state definitely their position here below according to His mind. The first is given in ver. 13, answering to righteousness, as we saw in the earlier qualities He endorses; the second in 14-16, answering to the outgoing energy of grace.
So salt corresponds to the inward, preserving, righteous character Christ had just described, while light (vv. 14-16) corresponds to the outgoing witness of grace.
Why "Salt"?
Kelly grounds the figure in the Old Testament, where salt was bound up with sacrifice and covenant:
The disciples were familiar with salt not only in ordinary life but in the oblation to Jehovah, "the salt of the covenant of thy God": "with all thine offerings thou shalt offer salt" (Lev. 2:13). And so we read of "a covenant of salt": as expressive figuratively of what was to be preserved inviolate and unchanging (Num. 18:19; 2 Chron. 13:5).
From that Kelly draws salt's double force — it speaks of God's preserving power answering to His holy nature:
If fire represents God's avenging judgment of evil, salt does no less clearly His preserving power in relation with Himself... as offered to God, our bodies even as a living sacrifice, we know and have the seasoning with salt that we may be kept pure and incorrupt, abhorring any working of flesh as vile and condemned in Christ's death.
F. B. Hole gives the same thought in simpler language, tying it directly to the believer's separation from the world:
F. B. HoleSalt preserves, and light illuminates. We cannot be like healthful salt in the earth if we are of the earth. We cannot be as a light lifted up in the world if we are of the world. Now nothing more helps to keep us distinct and separate from the earth and world than persecution from the world, no matter what form it takes. Persecuted for Christ's sake, the disciple is real salty salt, and he also emits a maximum of light. Does not this word of our Lord reveal to us the secret of much of our feebleness?
Hole notices something easy to miss: the salt-saying comes immediately after the beatitude on persecution. It is precisely under reproach for Christ's sake that the disciple is most unmistakably the salt.
Why "the Earth" and not "the World"?
Kelly presses a distinction many readers pass over. The Lord deliberately calls them salt of the earth, and reserves "world" for the next verse about light:
Let it be noticed that they, and only they, and they emphatically, were "the salt of the earth." The Lord does not say the salt "of the world." ... when thus distinguished as here, we may remark now in pointing out the force of our text, that "the earth" means that ordered scene where God had dealings beyond other parts. It was then as of old where Israel was set; as it was about to be enlarged by the outward profession of His name far beyond the land of Palestine. The Lord accordingly begins with that position of conserving purity, alike privilege and responsibility. "Ye are the salt of the earth."
The earth, in this use, is the sphere where God's name is owned — the professing scene. Inside that scene, the disciples are the one element that keeps corruption at bay.
J. T. McBroom puts the same thought in practical terms, linking it to the persecution in verses 10-12:
J. T. McBroomSuffering whether for the kingdom or the King was to be esteemed a favour, and it would have its bearing both on the present and the future... it also gave the present distinction of being in the ranks of heaven's most distinguished witnesses on earth, and set them in the line of divine testimony. They were the salt of the earth and the light of the world. Notwithstanding the persecution and hatred of men they were to be a force for good, able to meet and counteract in divine power the corruption that is in the world through lust, and shed a beneficent influence on all around them.
The Solemn Warning: "If the Salt Lose Its Savour"
The Lord does not leave the saying as a compliment. He attaches a grave condition. Kelly handles this with unusual weight:
But He adds words — most grave words — "If the salt lose its savour, wherewith shall it be salted?" Profession there would be, and an excellent thing it is, if it be a heart testimony to God, true not only in word but in deed. Here, at the beginning and still more clearly at the end of His communications the Lord prepares us to expect what soon and increasingly became evident how hollow and false it was to become; and He intimated by His question and comment that the true and holy savour if once lost would be irreparable. Whatever grace might work individually, or with a few here and there, the pure position cannot be restored. Salt is itself. Nothing outside can give the saltness that disappears. Wherewith shall it be salted?
That last sentence is the heart of it. Salt cannot be re-salted from outside. If the thing whose very office is to preserve loses its own character, there is no second preservative to restore the first.
Kelly then turns to the end of the verse — cast out, trodden under foot:
He goes farther, and pronounces its unfitness even for the useful purpose of fertilising supplied by that which is most offensive. Saltless salt is unavailing even to manure the earth. It is only fit to be thrown outside, and trodden under foot of men. And so it will be, as it has been. When Christianity vanishes and only a savourless Christendom remains, men have trodden it down as more worthless than Judaism or even Gentilism, and the more insufferable as so much prouder and more persecuting.
J. N. Darby, reflecting on the chapter, draws the same sorrowful application to the state of the professing Church:
J. N. DarbyHow evidently, in the Sermon on the Mount, the Lord speaks of those in the midst of evil, and who in fact had a heavenly, divine mind in the midst of it!... But if those so-called were the salt of the earth, what is it all become? What a judgment on the now professing Church!
Drawing the Threads Together
Matthew 5:13 does three things at once.
First, it defines the disciple's position. Christ does not say "you ought to become" or "try to be" — He says "Ye are." Those who own Him are placed by Him as the preservative element in a scene otherwise given over to corruption. It is the answering counterpart to the inward righteousness just described in the beatitudes.
Second, it measures that position by an impossible demand. What makes salt useful is its own intrinsic character. A disciple whose distinctness from the earth is lost cannot be restored by any external force. The testimony has no substitute outside itself — it is either itself, or nothing.
Third, it forecasts the history of profession. Kelly sees the warning already being fulfilled where mere savourless Christendom remains — a profession emptied of its preserving power, despised even by the men it once claimed to season. The verse is therefore not only personal ("keep your saltness") but prophetic, preparing the disciples for what the outward kingdom would become.
Put simply: to be salt of the earth is to carry, in the midst of a corrupt scene, the moral savour of Christ Himself — and the Lord will have nothing less.