“You yourselves and no other are the salt of the earth”. This is the best translation of Jesus’ words in Matthew 5:13. Jesus envisions a role for us no one else can fulfill. If we are not prepared to be the salt of the earth, no one else will be. It is no use looking to governments, scientists, philosophers or military figures to save civilization – only the church of the living God can rise to the task. If the church fails, there is no Plan B. Jesus does not envision a world where humanists and people of various religions will join forces to establish peace and harmony. Jesus was so “narrow-minded” as to insist that only His followers, empowered by His Spirit, would be able to do the job. The most common use for salt in the ancient world, in places with a hot climate and no refrigeration, was as a preservative. A small amount of salt rubbed into meat would slow its decay. Clear enough – we are to be a preservative. But how could Jesus speak of salt losing its saltiness? Anyone who has taken high school chemistry knows that salt, sodium chloride, is what chemists call a stable compound. In other words, it does not decay or become diluted over time. Was Jesus a poor scientist? The answer is found in the fact that in the ancient world salt, rather than being mined or produced as the product of evaporation from salt water, was found in salt marshes. It therefore contained many impurities. Because the salt itself was more soluble than the impurities, it could wind up being drained or leached out in the process of being transported, stored or used, thereby leaving most of the impurities but only a little of the pure salt. The residue was so diluted it was of little worth for preserving purposes. This was described as salt which had lost its saltiness.
Jesus then states that such salt is no longer good for anything except to be thrown out and trampled by men. According to scholars, salt that had lost its saltiness was used for a specific purpose in the ancient near east. It was scattered on the soil which covered the flat roofs of houses. The nature of its chemical composition was such as to harden the soil and prevent leaks in the roof. In those times, roofs were used as playgrounds for children or as meeting places for adults (much as we use patios or decks). Consequently, they were continually being trodden under foot, and this process was used, along with the sprinkling of diluted salt, to keep the roofs hard and leak-proof. What is tasteless salt good for? Only to be thrown out (or cast around) and trodden under foot. That was the only practical use it had left.
The message is clear. In order to be the moral disinfectant, the agent of health and wholeness in a world of decay and death, Christians must retain the full strength of what Jesus has put within them. When we come to Christ, we are given the potential of living with Christ’s nature and the ability that comes with that to affect the world around us. But along with it, we also carry the baggage of our fallen human nature. As we take the purity of what God has given us in Christ and carry it through this fallen world, we are continually confronted with the possibility of compromise, of letting our standards fall, of choosing to live with one foot in the kingdom and one foot out of it. If this takes place, the purity and strength of what we have in Christ will gradually be leached away, and all we will be left with is a pale copy of the real original. There must be no compromise with worldly standards, no letting down of our guard.
Otherwise, we will find ourselves thrown out of God’s purposes and trodden underfoot by the men, in such a way that, through our hypocrisy or inability to live up to the message we proclaim, we wind up contributing to the hardening of their hearts against God.