Jesus in the "Sermon on the Mount" used the words "Hell of Fire" or depending on the translation "Fire of Hell" as being the final destination of the ungodly, so what is the Hell of which he spoke? Here is the quote: -
"You have heard that it was said to those of old, 'You shall not murder; and whoever murders will be liable to judgement.' But I say to you that everyone who is angry with his brother will be liable to judgement; whoever insults his brother will be liable to the council; and whoever says, 'You fool!' will be liable to the hell of fire." (Matthew 5:21)
Hell is the final destiny of those who have not accepted the Christ as their saviour after they have passed through the great white throne of judgement, where they will be punished for their sin after the general resurrection and last judgement.
Hell is called "Sheol" in the Old Testament and "Hades" in the New Testament and simply translated means death and the grave. When Jesus spoke of "Hell Fire" in the beatitudes he illustrated it by pointing out the well known fires in the Valley of Hinnom close to Jerusalem that had been used for human sacrifice to pagan gods. This valley of death makes the point very forcibly that after the judgement those found wanting will hear the words
"Depart from me, you cursed, into the eternal fire prepared for the devil and his angels." (Matthew 25:41)
On the other hand those who found favour in the sight of God as a result of the atoning work of Christ, by grace through faith, will be spared eternal death as judgement for their sins and will hear the welcome words
"Come, you who are blessed by my Father, inherit the kingdom prepared for you from the foundation of the world." (Matthew 25:32)
G86
ᾅδης
hadēs
hah'-dace
From G1 (as a negative particle) and G1492; properly unseen, that is, “Hades” or the place (state) of departed souls: - grave, hell. (Hades = grave which means hell)
H7585
שׁאל שׁאול
she'ôl she'ôl
sheh-ole', sheh-ole'
From H7592; hades or the world of the dead (as if a subterranian retreat), including its accessories and inmates: - grave, hell, pit.
G1067
γέεννα
geenna
gheh'-en-nah
Of Hebrew origin ([H1516] and [H2011]); valley of (the son of) Hinnom; gehenna (or Ge-Hinnom), a valley of Jerusalem, used (figuratively) as a name for the place (or state) of everlasting punishment: - hell.
G5020
ταρταρόω
tartaroō
tar-tar-o'-o
From Τάρταρος Tartaros̄ (the deepest abyss of Hades); to incarcerate in eternal torment: - cast down to hell.
And he said unto Jesus, Lord, remember me when thou comest into thy kingdom. And Jesus said unto him, Verily I say unto thee, To day shalt thou be with me in paradise. (Luk 23:42-43)
My own understanding is that while their mortal bodies remained in the grave (Hell), their spirits ascended into heaven as in the resurrection.
The fiery furnace, I believe is a reference to the common custom of cremation, and as with the grave it is for all eternity. The end; but neither the grave nor the fiery furnace of can destroy the soul of the believer.
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