Two famous metaphors from the mouth of Jesus, taken from Matthew 5:13-14. The first one is meaningless in English, the second is understandable. Why is that? Well, the answer is simple enough. The English word ”light” has both a basic/physical/literal meaning and a metaphorical usage, but ”salt” has no metaphorical meaning or usage in English.
Let me first comment on light, since that is the easier one. My Collins dictionary says about light: ”mental understanding or spiritual insight.” The light metaphor is common in the NT. In John’s Gospel we find statements like: ”The true light that gives light to everyone was coming into the world.” (1:9 about Jesus). 8:12 says: ”I am the light of the world.” 9:5: ”While I am in the world, I am the light of the world.” 12:44-46: ”Whoever believes in me does not believe in me only, but in the one who sent me. The one who looks at me is seeing the one who sent me. I have come into the world as a light, so that no one who believes in me should stay in darkness.”
The metaphor of light in the NT does not so much refer to mental understanding as it refers to spiritual insight based on revelation from God. Those people who became disciples of Jesus became ”people of the light” (Luke 16:8). Jesus would not stay in the world to continue to give his light to it, but he sent the Holy Spirit to continue to give light and revelation. Once Jesus had left the world, the disciples were to take over the ministry of light-bringers, but it had to be based on revelation from God – in addition to what Jesus had taught them, which was also revelation from God. In Matthew 5:14, Jesus was preparing his disciples to become apostles, saying: ”You are the light of the world – let your light shine before people, so that they may see your good deeds and praise your Father in heaven.” Those good deeds are not their own mental understanding nor necessarily their good behavior, but it is the spiritual power and inspired wisdom that comes from God, and that is why God is to be praised for it. Jesus said the same about himself. He only spoke what his Father told him to say and he only did what his Father told him to do.
When Peter understood that Jesus was the Messiah as stated in Matt 16:16, Jesus immediately responded: ”Blessed are you, Simon son of Jonah, for this was not revealed to you by people, but by my Father in heaven – and on this solid foundation I will build my church.” Matt 11:25-27 is a basic passage for our understanding of the concept of ministry and wisdom based on revelation from God: ”Jesus said: I praise you, Father, Lord of heaven and earth, because you have hidden these things from the wise and learned, and revealed them to little children. Yes, Father, for this is what you were pleased to do. All things have been committed to me by my Father. No one knows the Son except the Father, and no one knows the Father except the Son and those to whom the Son chooses to reveal him.” Of course, the ”little children” is a metaphor for people who are open and willing to be taught, to receive revelation from God. The philosophers of this world base their mental understanding on human reasoning rather than spiritual revelation. Paul has something to say about that, too. He was a learned man, but had to re-think his whole understanding of God and spiritual truth from scratch when Jesus stopped him in his tracks. He writes in Phil 3: ”But whatever were gains to me I now consider loss for the sake of Christ. What is more, I consider everything a loss because of the surpassing worth of knowing Christ Jesus my Lord, for whose sake I have lost all things. I consider them garbage so that I can gain Christ – I want to know Christ.” In Galatians he emphasized how Jesus had revealed himself on the way to Damascus: “when God … decided to reveal his Son to me … my immediate response was not to consult any human being.” And he says: ”I want you to know, brothers (and sisters), that the gospel I preached is not of human origin. I did not receive it from a human being, nor was I taught it; rather, I received it by revelation from Jesus Christ.” Paul tells us about revealed, inspired wisdom as opposed to worldly wisdom in 1 Cor 1: “For it is written: “I will destroy the wisdom of the wise; the intelligence of the intelligent I will frustrate.” Where is the wise person? Where is the teacher of the law? Where is the philosopher of this age? Has not God made foolish the wisdom of the world? For since in the wisdom of God the world through its wisdom did not know him, God decided through the foolishness of what was preached to save those who believe. Jews demand signs and Greeks look for wisdom, but we preach Christ – the power of God and the wisdom of God. For the foolishness of God is wiser than human wisdom.”
I am saying this to show that the light/wisdom the NT talks about is not human wisdom or wit or philosophy or even the accumulated religious knowledge of the “teachers of the law.”
Paul’s talk about wisdom and foolishness leads us to the first metaphor in Mat 5:13: ”YOU are the salt of the earth/land/world, but if the salt should become foolish, with what can its saltiness be restored?” The Greek word μωραίνω means ”make foolish.” It occurs here in a passive form meaning ”become foolish.” Another way of saying the same thing would be ”lose your wisdom.” There is no evidence that this Greek word could mean what it is often translated as. NIV says ”loses its saltiness,” and by doing so they have lost the meaning and the metaphor. If only they had kept ”should lose its wisdom” or “should become foolish” the reader would have had a chance to understand that ”salt” is a metaphor for those who have received spiritual wisdom and bring light to others, while “saltiness” is a metaphor for spiritual wisdom, the kind of wisdom revealed to the disciples by Jesus.
Jesus did not say these words in Greek, but in Hebrew or Aramaic. Whatever the case, the word spoken by Jesus was probably tapel תָּפֵל because this word has two senses which fits perfectly with the salt metaphor. It can mean either to be tasteless or to be foolish. The Greek translator chose to render the sense of losing wisdom in order to give a clue to the topic of the metaphor, not just describe the illustration of salt.
When a metaphor is translated literally into a language that does not have the same or a very similar way of speaking metaphorically, the readers will automatically try to make sense of a nonsense saying. They will look for possible uses of salt within their own culture or maybe in the ancient culture. Are the disciples supposed to make the earth/world more tasty? No, that is nonsense. Are they supposed to somehow preserve the earth/world? Hardly. We don’t use salt as a metaphor for wisdom as the rabbis sometimes did. The Exegetical Summaries quote three commentaries for the following statement: ”In Rabbinic literature salt often stood for wisdom [Mor, NCBC, TNTC2].” Mor=Morris, NCBC=New Century Bible Commentary, and TNTC2=France, R. T. The Gospel According to St. Matthew: An Introduction and Commentary. The Tyndale New Testament Commentaries. I have looked at Morris and France, but did not find their comments very helpful. Once we accept that ”saltiness” refers to spiritual wisdom, all problems are solved. It is not important to ask whether salt can lose its saltiness. It is important to ask whether disciples can lose the spiritual wisdom and revelation given to them. Jesus warns that this should not happen, because how will you return to your former state of wisdom? What wisdom can be used to make you wise again? Hebrews 6 has a similar thought: ”It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, who have tasted the goodness of the word of God and the powers of the coming age and who have fallen away, to be brought back to repentance. To their loss they are crucifying the Son of God all over again and subjecting him to public disgrace.”
I wish we could regain and rediscover the saltiness of the words of Jesus – and of Paul in Col 4:6.