Matthew 5:13 Commentary and Bible Study

How much Christ says in so few words! What a novel, powerful, and interesting illustration this is! The earth of course means the inhabited earth, the people who live on it. ‘You, who are my disciples, are the salt of the earth.’ The earth tends to go to putrefaction because of human sin. God’s people are in the world to retard that process by acting like salt, like a preservative. At the same time they fulfil another function of salt and give taste: it is for their sake that God does not immediately judge the world, and lets it go to its final conclusion (Matthew 13:29; Romans 9:22-23). Take away the church, and everything will be hurtling to judgement at the end of time. The Lord has just spoken of persecution. That is unpleasant and hard to face, and there are different ways they might try to avoid it, but Christ’s disciples must not yield to these temptations. One way is to become less distinctive: that is dealt with in this verse. Another way is to hide the fact that they are Christ’s disciples: that is dealt with in the next verse.Salt is pervasive; it permeates and affects what it comes into contact with. You never know what will become of your testimony. If it is added to anything it makes a difference to it. Salt is significant because it is so distinctive. This is all about the believer’s mission and the believer’s work. The believer’s life has been defined by these eight Beatitudes of God’s favour and happiness in Christ, and because these are in such stark contrast with the lifestyle of the unbeliever, that will make a strong impression.The believer must resist the temptation to become like the world. That would certainly remove the offence of the gospel and reduce persecution, but it would be to lose his God given function in the world. The world must be convicted of its sin, and although the Spirit works directly in the conscience of unbelieving men and women, he also does so through the conduct of his people which the world observes. By not doing as they do, we convict them, for we judge the things they do as wrong. That is the salt doing its work, and it may sting in the process, just as salt stings when put in a cut. With what can you salt salt? It is the very thing which is supposed to do the preserving. But if the salt has become corrupt and lost its saltiness, no one would bother to salt the salt. It is not worth preserving, for its one great function is to act as a preservative, and if it has lost that function it is good for nothing. Christ’s disciples are of course those whom he loves, and who he desires greatly to have with him in eternity. However, they are precious just because he has created a new character in them, and that distinctive character has ceased to be there if they are no longer acting as salt to a lost world.‘It is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.’ The distinctive lifestyle of the believer does not earn God’s favour, but it marks him out as one who God has converted and changed. There are those who fall away and go back to being like worldlings all over again. Just as men discard salt once it loses its one useful property, so God will reject those whose heart have never truly been changed and who are reabsorbed by the world.