Commentaries
English
Matthew
  
b) The Purpose of the Sermon on the Mount: The Application of the Law of God
(Matthew 5:13-16)
13You are the salt of the earth; but if the salt loses its flavor, how shall it be seasoned? It is then good for nothing but to be thrown out and trampled underfoot by men. (Mark9:50; Luke14:34-35)


Food without salt has no savor. Such is the world when there are no active followers of Christ. It loses the true love. As salt preserves food from putrefaction, so the message of Christ and its bearers keep the world from ending in total darkness. Just as salt compensates the loss of some substances of the body, the gospel builds the new life in those who are dead in sins. Without salt, human life cannot be sustained. Believers should have their lives seasoned with the gospel. The doctrine of the gospel is a “salt,” it is penetrating, quick, vivid and powerful. It reaches the heart. It is cleansing, relishing, and it preserves from putrefaction.
Salt was also required in the sacrifices (Leviticus 2:13) and in Ezekiel’s mystical temple (Ezekiel 43:24). Now Christ’s disciples, having themselves learned the doctrine of the gospel and being employed to teach it to others, were as salt. Thoughts and affections, words and actions, all are to be seasoned with grace (Colossians 4:6).
This is what they are to be in themselves. What should they be to others? They should not only be good but do good and influence the minds of people, not to serve secular interests of their own, but that they might transform others into the taste and relish of the gospel. Mankind, lying in ignorance and wickedness, was unappetizing, ready to putrefy, but Christ sent forth his disciples, who by their lives and testimonies were to season it with knowledge and grace, and so to render it acceptable to God, to the angels and to all who desire the divine spirit.
If not, they are as salt that has lost its savor. If you, who should season others, are yourselves unsavory, empty of spiritual life, grace and vitality, your condition is sad, for you are in a disastrous state. “Wherewith shall it be salted?” Salt is a remedy for unsavory food, but there is no remedy for unsavory salt. Christ will give a man a flavor; but if that man will take up and continue the profession of it, and yet remain flat and foolish, graceless and insipid, no other doctrine and no other means can be applied to make him savory.
If the salt loses its flavor, it is then good for nothing. What use can it be put to, in which it will not do more harm than good? As a man without sense, so is a Christian without grace. He faces ruin and rejection. He shall be “cast out” – expelled from the church and the communion of the faithful, where he is a blot and a burden, and he will be rejected as trodden under foot of many.
Christ is inviting you to partake in building and preserving a new world amidst the corruption of our civilization. So do not be deceived by the thought that you can change people of our earth by means of your abilities, for whoever trusts human activities shall lose his message, become futile in words and in conduct, and people shall mock him. So do not reject the message of the gospel for it alone creates in you an ability to be the salt of the earth; otherwise people will reject you because of the insincerity of your love.

Question
What does it mean that Christ invites you to be “the salt of the earth?”