When I was young and any injury happened to me, my dad had generally one cure in mind – salt. This was especially true in the summer, as I was (still am) one of those people that just gets absolutely swarmed by mosquitoes. I would have cuts and scabs cover my legs and many on my arms, and the solution in his mind was the beach. Mostly because he just liked going there, but if something couldn’t be cured by salt, you had to add come sun also to, ‘dry it out.’ In winter drinking warm salt water and going outside was the general cure. My brother and I literally had salt put into our wounds, but you get the point – he was a raving madman. However, as I was researching this passage, I came across this quote from Pliny the Elder in his major work, Natural History, – ‘Nothing is more useful than salt and sunshine’ (in Latin, Sale e Sole, so there is a little wordplay, too).
Turns out, the benefits of salt, including its healing power was well known in the ancient world. The many uses of salt included, preservation, flavor, and disinfectant. Salt was also a symbol of loyalty and was used in sacrifices. Famously, Roman soldiers were paid in salt (sale in Latin) which lead to our word salary today. The most common use of salt, and the one that the disciples would most identify with, is as a preservative. Salt prevents decay. Christ is calling on the disciples to prevent decay of the world rotting from sin. This likely has to do with moral decay as the disciples preserved the Law. The word usually translated ‘earth’ here is the same as the word land. Whenever we read the Bible the word ‘land’ should stick out to us as that was the covenant promise to Israel.
Relatedly, when we see ‘world’ we should think gentiles, and/or culture of the time. So what does light do? Most simply put, it illuminates the darkness. Israel, and Christ’s disciples, know God and they are command to remember God and keep his law. The gentiles do not know God. Therefore, they are in darkness. As disciples, we are to give light to those in darkness. That is, preach the Gospel, do good works to glorify God, and bring the knowledge that we have to that whom haven’t yet heard.
There are many verses related to this concept of light. In Isaiah 42 and 49, we are told the True Light is the suffering servant (that is, Christ to come). In Romans 2:17, Paul considers the Jews to think they are the light to the gentiles. We are told that darkness fears the light. In John 5, John the Baptist is called ‘a burning and shinning lamp.’ Of course, John the Baptist is one of the great models of Evangelism.
So, the value of salt and light would be well known the ancient world; a world that didn’t have electricity, and therefore lacked refrigeration and ‘light’ as we know it today. I’ll wrap up with what John Stott sees as the three lesson from these verses.
- There is a fundamental difference between the Christian and the non-Christian, between the Church and the World.
- We must accept the responsibility the distinction puts on us.
- We must see the twofold Christian responsibility of: Preventing decay (salt) and illuminating darkness (light).
It is easy enough to say to Christian, go be salt and light, but as the recent public discussions (from the ‘Benedict Option’ to whatever it is Evangelicals are doing with Trump) have shown, it isn’t that simple. Fundamentalism and monasteries pull us too far from the world, they are the equivalent of putting the lamp under a basket, or as I read one criticism using – salt never did any good sitting on a shelf. Likewise, we can’t just join the world, especially today in the ‘everyone does right in their own eyes’ of moral relativism. We have to be the ones to preserve the moral laws of God. Just remember, at work you may be the only one to view life with moral absolutes, you may be the salt that is preventing decay, or in your neighborhood, you may be the only light your neighbor sees. They may be living in darkness, and it is incumbent on you to shine the Light of Christ into their lives. Salt and light is an incredibly responsibility, one I think most of us do not take seriously enough.
Commentaries used in this series:
Sermon on the Mount (The Story of God Bible Commentary)
The Message of the Sermon on the Mount (Matthew 5-7 : Christian Counter-Culture)
Studies in the Sermon on the Mount
Matthew (Baker Exegetical Commentary on the New Testament)
The Expositor’s Bible commentary : Matthew, Mark, Luke, with the New international version of the Holy Bible (Expositor’s Bible commentary, Vol.8)
Matthew: An Introduction and Commentary (Tyndale New Testament Commentaries)
New Bible Commentary