The expression “their worm dieth not and the fire is not quenched” is a phrase that is found in the Bible.  Perhaps it conjures up a picture of people writhing in everlasting pain as they are tormented in hell.  Is this verse talking about eternal worms and eternal hell fire?

Let’s look at the passage in the Gospels where it is mentioned, Mark 9:43-50.

Mar 9:43  If your hand causes you to sin, cut it off. It is better for you to enter into life maimed, rather than having two hands, to go to hell [gehenna], into the fire that shall never be quenched—
Mar 9:44  where ‘THEIR WORM DOES NOT DIE AND THE FIRE IS NOT QUENCHED.’
Mar 9:45  And if your foot causes you to sin, cut it off. It is better for you to enter life lame, rather than having two feet, to be cast into hell [gehenna], into the fire that shall never be quenched—
Mar 9:46  where ‘THEIR WORM DOES NOT DIE AND THE FIRE IS NOT QUENCHED.’
Mar 9:47  And if your eye causes you to sin, pluck it out. It is better for you to enter the kingdom of God with one eye, rather than having two eyes, to be cast into hell [gehenna] fire—
Mar 9:48  where ‘THEIR WORM DOES NOT DIE AND THE FIRE IS NOT QUENCHED.’
Mar 9:49  “For everyone will be seasoned with fire, and every sacrifice will be seasoned with salt.
Mar 9:50  Salt is good, but if the salt loses its flavor, how will you season it? Have salt in yourselves, and have peace with one another.”

Is this passage saying that the fate of sinners is eternal hell fire?  No.  The Bible is clear that the fate of sinners is death. 

Rom 6:23  For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.

In other words what we earn (or get) for sinning is death, not eternal torment in hell.  The same truth is also found in the Old Testament.

Eze 18:4  “Behold, all souls are Mine; The soul of the father As well as the soul of the son is Mine; The soul who sins shall die.

But what did Jesus Christ mean when He used this expression “their worm does not die and the fire is not quenched”?  Christ was quoting from Isa 66:24 – the last verse of the last chapter of the book of Isaiah.

Isa 66:23  And it shall come to pass That from one New Moon to another, And from one Sabbath to another, All flesh shall come to worship before Me,” says the LORD.
Isa 66:24  “And they shall go forth and look Upon the corpses of the men Who have transgressed against Me. For their worm does not die, And their fire is not quenched. They shall be an abhorrence to all flesh.

The word Jesus Christ used that is translated as “hell” is gehenna.  Gehenna is a word of Hebrew origin and simply means “valley of Hinnom”.  The valley of Hinnom was a small steep valley just south Jerusalem.  According to various commentaries, this valley became the city dump.  Here dead bodies of animals and criminals, and all sorts of rubbish, were thrown onto permanently smouldering fires.

If a carcass of a dead animal or criminal was thrown in the valley of Hinnom, or gehenna, it had one of two fates. 

1. If the carcass was thrown onto a place where there was no fire, then flies laid their eggs on the carcass, and their eggs hatched into worms or maggots which then ate the carcass until there was nothing left except bones. 
2. If the carcass was thrown onto a fire, then it kept burning until it was all burnt up. 

In both cases the destruction was total.  The worms or maggots in the valley of Hinnom completely consumed the carcass.  Likewise, the fire in the valley of Hinnom completely consumed the carcass. 

When Jesus Christ referred to people going

to hell [gehenna], into the fire that shall never be quenched—where their worm does not die and the fire is not quenched,

He was talking about total destruction.  In other words to rephrase Mar 9:43-48.

If your hand causes you to sin, cut it off. It is better for you to enter into life maimed, rather than having two hands, be totally destroyed
And if your foot causes you to sin, cut it off. It is better for you to enter life lame, rather than having two feet, to be totally destroyed
And if your eye causes you to sin, pluck it out. It is better for you to enter the kingdom of God with one eye, rather than having two eyes, to be totally destroyed.

In other words, if something in our life is causing us to sin, we need to cut it out, get rid of it.  For it is better to gain eternal life without enjoying those things that cause us to sin, than to enjoy them in this life and then lose out on eternal life.

But what do the next two verses in Mark mean?

Mar 9:49  “For everyone will be seasoned with fire, and every sacrifice will be seasoned with salt.
Mar 9:50  Salt is good, but if the salt loses its flavor, how will you season it? Have salt in yourselves, and have peace with one another.”

Verse 49 is almost certainly a reference to the offerings instructed in Leviticus chapter 2. 

Lev 2:13  And every offering of your grain offering you shall season with salt; you shall not allow the salt of the covenant of your God to be lacking from your grain offering. With all your offerings you shall offer salt.

Lev 2:16  Then the priest shall burn the memorial portion: part of its beaten grain and part of its oil, with all the frankincense, as an offering made by fire to the LORD.

The grain offering had salt added to it and was burnt with fire.  In Romans 12:1 Paul exhorts us to present our bodies as living sacrifices. 

Rom 12:1 I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service.

If we are a living version of this sacrifice, then since the grain offering needed salt and went through the fire, then we need to be seasoned with salt and we must at times go through fiery trials. 

But where does the salt come from?  In verse Mark 9:50, it says, “Have salt in yourselves”.  Also, in Mat 5:13, Christ said, “You are the salt of the earth”, and He immediately followed it with “You are the light of the world”.  In other words, we need to set a right example for others by our behaviour.  To be an acceptable living sacrifice to God we must be seasoned with salt; we must be obeying God.

The meaning of Mark 9:49-50 is that we are a living sacrifice.  Just as the grain offering was seasoned with salt and went through fire, so also, we must set the right example and at times experience fiery trials. 

So how does this link in with the earlier part of the passage, where Jesus said if something causes you to sin, cut it out of your life?  Cutting sinful things out of our lives might be painful—a trial of sorts—but we must do it.  We must be a pleasing living sacrifice to God.