You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot. (Matthew 5:13)

The Greek word is ἅλας halas (Strong’s 217) and it means common table salt (sodium chloride).

Jesus uses the analogy of salt as recorded in the synoptic gospels; above in Matthew it is in the context of witness.

Again, in the context of sin and damnation (Mark):

And if your eye causes you to stumble, pluck it out. It is better for you to enter the kingdom of God with one eye than to have two eyes and be thrown into hell, where

 ‘the worms that eat them do not die,
and the fire is not quenched.’

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

(Mark 9:47-50 – quoting Isaiah 66:24)

And within the context of discipleship and falling short (Luke).

‘Salt is good, but if it loses its saltiness, how can it be made salty again? It is fit neither for the soil nor for the manure heap; it is thrown out. (Luke 14:34-35)

Common to all the entries is the phrase ‘if salt loses its saltiness, how can it be made salty again’.  This then points to true discipleship and seems to echo the statements on apostasy in Hebrews 6 and 10, but Jesus is making a different point here.  The Greek word that is translated as ‘lost its saltiness’ is μωραίνω mórainó (Strong’s 3471) and means to become useless, tasteless or insipid, figuratively to become a fool, or be foolish.

The sense then is more akin to Jesus’ admonishment of the church of Laodicea:

I know your deeds, that you are neither cold nor hot. I wish you were either one or the other! So, because you are lukewarm – neither hot nor cold – I am about to spit you out of my mouth. (Revelation 3:15-16)

Lukewarm water (as was that supplied to the city sourced from distant hot springs) just like slightly salted water is only good for an emetic and Jesus will vomit any from his body, that is the church.  Sham piety is useless just as is the disciple that has lost his way and has become foolish.

Jesus is using the analogy of salt to describe the characteristics of his true and faithful followers.  Firstly, they a distinctive.  Salt, one of the four traditional taste sensations (sweetness, sourness, saltiness, and bitterness*).

Any in Christ then are separated from the world that is allied against him; each is morally distinct and spiritually set apart; however, to be of any use, salt has to be introduced and combined with foods.  Christians are required to mingle, to mix with others for them to useful within God’s kingdom building.

Along with adding flavor to food, salt has another quality and use, that of a preservative.  The world is rotten with sin and can never be fixed by human intervention for perfection is God’s work, but the intervention of God’s people is required to slow the rot.

But this engagement with the world must not be made with compromise.  Should a Christian take on (regain) worldly values and morality then that person is no longer any use to God.  To follow Christ must necessarily be counter-cultural whatever the prevailing ethos.

This sense of the Christian being lost back to sin and falling short combines the three references in the Synoptic Gospels.  It is the seen in the fate of the third seed in the parable of the sower.  Having fallen among thorns ‘which grew up and choked the plants, so they did not bear grain’:

…like seed sown among thorns, (others) hear the word; but the worries of this life, the deceitfulness of wealth and the desires for other things come in and choke the word, making it unfruitful. (Mark 4:18-19)

Jesus is clearly warning that being set apart from the unbelieving humanity, while mixing and mingling in order to be His witness, is extremely difficult.

Therefore, since we are surrounded by such a great cloud of witnesses, let us throw off everything that hinders and the sin that so easily entangles. And let us run with perseverance the race marked out for us, fixing our eyes on Jesus, the pioneer and perfecter of faith.  (Hebrews 12:1-2)

And there is only one way to ensure ‘saltiness’ and that is to remain obedient to Jesus’ commands.

Blessed rather are those who hear the word of God and obey it.  (Luke 11:28)

As Jesus’ half-brother says:

….be doers of the word, and not hearers only, deceiving yourselves.

(James 1:22 ESV)

 

Note – sodium although the sixth common element on earth is actually ten times rarer than silicon, while chlorine is twenty-first in abundance and is some two thousand times rarer than aluminium; what makes salt so common is not the abundance of its elements but its solubility in water and its chemical stability in once dissolved in water along with its crystalline form.

Note – a fifth is now identified ‘umami’ or deliciousness