Jesus tells his audience for the Sermon on the Mount that they are the “salt of the earth.” What, exactly, does that mean? I thought I knew before I started writing this. Part of the purpose of this blog is to work out my own thoughts, even if it’s in public!

Matthew is the only one to use the phrase “salt of the earth” but Mark and Luke both talk about salt losing its saltiness, with variations. The variations may help us figure out what’s happening.

Matthew: You are the salt of the earth. But if salt loses its flavor, how can it be made salty again? It is no longer good for anything except to be thrown out and trampled on by people.

Mark: Everyone will be salted with fire. Salt is good, but if it loses its saltiness, how can you make it salty again? Have salt in yourselves, and be at peace with each other.

Luke: Salt is good, but if salt loses its flavor, how can its flavor be restored? It is of no value for the soil or for the manure pile; it is to be thrown out. The one who has ears to hear had better listen!

Let’s start with Mark, whose text is honestly confounding. Jesus is talking about how avoiding hell (Gehenna in this case, we’ll talk about “hell” later) is worth any cost. And then he says “everyone will be salted with fire.” (Or maybe he says “Every sacrifice will be salted with salt.” Or maybe both, the manuscripts vary.) As best I can tell, nobody is sure what this means. Jesus seems to jump from avoiding hell to being salted with fire, to salt losing saltiness, to having salt in ourselves and being at peace with each other. There’s no obvious thread here.

Now, I think there is a train of thought happening here, but I’m going to have to save that for another post. For now, let’s look at the words being used.

The word for “salted” shows up nowhere else in the New Testament except Matthew 5 and Mark 9. But in the Old Testament it does show up in Leviticus 2:13 and in Ezekiel 16:4.

That Ezekiel passage is particularly interesting, because it implies newborns should be salted. Why, exactly? Well, again, nobody seems to know, but it’s been a thing discussed for a long time. So is Jesus saying fire will do for us what salt does for newborns, some form of cleaning and purification? But then, why would we have salt in ourselves? The language doesn’t quite fit.

In the Leviticus 2 passage, it’s specifically grain offerings that have to be salted, so at least it makes some sense to talk about having salt in yourself, if you (or whoever Jesus is addressing here) are the grain offering. And grain offerings were offerings by fire, so that’s consistent at least with everyone being salted with fire. The fire applied to the people (which is presumably unpleasant) is like the salt of the grain offering, perhaps suffering to be made a holy offering to God, much as Paul compares himself to a drink offering. Maybe that’s something Mark has going on.

Except for Luke, where that makes no sense at all. Luke talks about salt being fit for soil or a manure pile, not for offerings to God. This is salt as fertilizer. Their salt wouldn’t have been our chemically pure table salt, it would have been obtained by evaporating sea water, and sea salt has all sorts of great plant nutrients in it. Salting the earth doesn’t ruin it, it turns it into a productive field, because really, who would be stupid enough to ruin perfectly good land in a context where your society needs every scrap of food it can grow? Now weirdly, in Luke we get no explanation of why Jesus suddenly starts talking about salt. He doesn’t compare it to people or make any apparent point with it. This may require further consideration in another post.

Can we square salt as fertilizer with Mark’s usage? Mark’s “have salt in yourself” makes sense, if we are ourselves the manure the salt is mixed into, so we can be fertilizer. So while Matthew says “you are the salt” and Mark says “have salt in you,” they’re using slightly different metaphors, but either way the purpose is for us to apply that salt to the world, preparing the world for growth. That’s consistent with the common agricultural/harvest metaphor for the coming of the Kingdom of God; the purpose of God’s people is to prepare the world for the growth of the Kingdom. But what does it mean for everyone to be salted with fire?

Now I want to get into the Greek a bit. I claim no expertise here, but as far as I can tell, the word here translated “everyone” is really just “all.” All will be salted with fire. The idea that it’s “all people” is an assumption by the translators from context, but it could also mean “all the world” or “everything.” Now, the idea that everything will be salted by fire makes more sense, if we understand salting to mean “preparing for new growth.” The world will be prepared for new growth by fire coming to destroy the corruption that already exists, and the disciples will be part of that as long as they don’t become corrupt and lose their own potential for facilitating that growth in the world.

There are some very smart people who read the salt passages differently than I do, of course. If you’re convinced that salt really is about purification rather than fertilization, I’m not claiming to be an authority that can tell you otherwise. But I do think this is a very significant theological point. If we assume these passages to be directed at all of Christ’s disciples, we ourselves should have salt in us, and be salt to the world. But are we just preserving the world against destruction, or are we making the world ready for new growth? These are very different perspectives of what exactly our purpose is.

I would suggest that God’s acts of creation are not just bringing something from nothing, they’re bringing order from chaos. As we have been assigned the task of reflecting God’s image to creation, we are invited to participate in that ongoing work of creation. Clearly we are not here to merely preserve what we have been given, but to make things grow. God’s people are the fertilizer of the earth; be sure to keep that fertilizer in yourself, so you can do the job you were meant to do.