In the King James Version, the word hell occurs 54 times, but in almost every case it is a translation of one of three different words, each with its own meaning. So to understand hell, we really need to understand the original Hebrew and Greek words that are translated hell. These are: Sheol, Hades and Gehenna.
Sheol is a Hebrew word meaning grave. The first use is of Jacob speaking of how he will go to the grave (Genesis 37:35). So David also wrote
For thou wilt not leave my soul in hell; neither wilt thou suffer thine Holy One to see corruption. (Psalm 16:10 KJV)
This verse of David is not only about himself, it is also a prophecy of Jesus who did not remain in the grave. (See Acts 2:23-32 for Peter’s explanation of the prophecy) . In the original Hebrew David is using the word Sheol, and some English Bibles use Sheol instead of hell here (e.g., NKJV). Others use grave (e.g., NIV).
Hades is the Greek translation for Sheol. In the Greek translation of the Old Testament, which was made for Jews living outside Palestine and then adopted by the early church, verses like Psalm 16:10 (above) were translated “you will not leave my soul in Hades” (exactly as Acts 2:23-32). It was also used figuratively for the power of the grave, for example:
O Death, where is your sting? O Hades, where is your victory? (1 Corinthians 15:55 NKJV)
Most modern English versions either leave Hades untranslated or translate it as ‘grave’ as in this verse:
O death, where is your sting? O grave, where is your victory? (American Standard Version)
Unfortunately the word was also used in pre-Christian Greek mythology to mean the netherworld or abode of the dead. The popular misconception of ‘hell’ in English comes from this pre-Christian use of the word. It is very important to distinguish the difference between the Jewish and pagan views of Hades.
For in Hades, where you are going, there is neither working nor planning nor knowledge nor wisdom. (Ecclesiastes 9:10 in the Greek Old Testament which translates Sheol from Hebrew into Hades in Greek).
O Lord, let me not be put to shame, for I call upon you; let the wicked be put to shame; let them be silent in Hades. (Psalm 31:17 Greek).
See also Psalm 94:17, Psalm 115:17 where the idea of silence in the grave is repeated.
The view of those Bible verses is very different from the typical view of Hades among pagans, such as in this speech given by the Greek poet Pindar at a Chariot Race in 462 BC:
… sacred kings who took their allotted places in Hades, and somehow below the earth they hear, in their minds, great excellence sprinkled with gentle dew by the outpourings of victory-songs. (Pindar – Pythian Odes 5.96)
From the above comparison it is clear that the view of Pindar, and other Greeks, was different from the Old Testament view of the Grave. By the time of Christ this pagan view of Hades had begun to spread among the Pharisees and others who had become influenced by Greek ideas. Despite this, overall the New Testament holds strictly to the Old Testament view of Hades as a place of silence where “the dead know nothing” (Ecclesiastes 9:5). The only exception to this is one biblical passage where the popular Greek-influenced meaning of the word Hades seems to be intended, and that is in the elaborate parable of Luke 16 on the rich man and Lazarus. See here for an analysis of this difficult passage.
Gehenna is another Greek word translated as “hell” in English versions. In fact it is originally a place name referring to the Valley (in Hebrew Ge) of Hinnom, south-west of Jerusalem. You can find this valley marked on the maps of Jerusalem at the back of some Bibles. The Valley of Hinnom had a terrible history as the site of a temple to the pagan god Moloch where children had been sacrificed. This so disgusted the Old Testament prophets that the valley became a symbol of judgment — firstly on the priests of Moloch, later on others opposing God. This verse below is the final verse of Isaiah and concerns the aftermath of a great battle at the Last Judgement:
And they shall go out and look on the dead bodies of the men who have rebelled against me. For their worm shall not die, their fire shall not be quenched, and they shall be an abhorrence to all flesh. (Isaiah 66:24 ESV)
At the time of Jesus the rabbis also used Gehenna as a symbol of the Last Judgement.
the best of quack-doctors are destined for Gehenna (Kiddushin 82a, Soferim 15.10 fol. 41a, Abot de Rabbi Nathan 36.5)
And Jesus actually quoted the last verse of Isaiah in reference to Gehenna in his parables:
And if your eye causes you to sin, tear it out. It is better for you to enter the kingdom of God with one eye than with two eyes to be thrown into hell, ‘where their worm does not die and the fire is not quenched.’ (Mark 9:47-48, citing Isaiah 66:24 ESV)
In the above example Jesus is using Isaiah’s prophecy about the Valley of Hinnom (Gehenna) in the same way as the Old Testament prophets used the Valley of Hinnom: as a symbol of the total destruction of the wicked. The worms in the verses are not the “souls” of the dead, but literal worms literally consuming dead corpses. Likewise the fire is not the fire of torture — such as seen in medieval paintings of the devil tormenting souls in Hell — but simply a reference to the ancient custom to pile up the bodies of enemies after a battle and burn them to prevent the spread of disease.
The other important reference by Jesus to Gehenna is the following passage:
Do not be afraid of those who kill the body but cannot kill the soul. Rather, be afraid of the One who can destroy both soul and body in Gehenna. (Matthew 10:28 in Greek, most English versions have “in Hell”)
This verse does not make sense if viewed with the traditional medieval view of Hell as a place where souls are not destroyed but tormented, but Jesus’ words makes perfect sense when the reference to the Old Testament view of Gehenna is understood. In other words, Jesus is saying, don’t be afraid of human persecutors who may kill you, but they cannot take away your hope of the resurrection. Instead, fear God who can both take away your life now, and your hope of eternal life. The destruction from God is so complete, it is like a corpse that has been thrown into Gehenna. To understand Matthew 10:28 also requires understanding of Jesus’ teaching that those responsible to God would be raised to judgement.
Do not marvel at this, for an hour is coming when all who are in the tombs will hear his voice and come out, those who have done good to the resurrection of life, and those who have done evil to the resurrection of judgment. (John 5:28-29)
…having a hope in God, which these men themselves accept, that there will be a resurrection of both the just and the unjust. (Paul in Acts 24:15)
For more information, see Heaven and hell.