Fire and Brimstone Hell/Analysis
The concept of Fire and Brimstone Hell comes from a distinction Lost in Translation. The word "Hell" is used as a translation for four words used in the initial writing of The Bible in its original languages: Sheol, Hades, Tartarus, and Gehenna. Sheol is a Hebrew word and Hades is Greek; both mean the same thing, the abode of the dead for all humans, whether good or bad, at least until Armageddon, and used in conjunction with Ecclesiastes 9:5 would refer to Cessation of Existence. Hades is mentioned as a place of torment only once: in Luke 16:19-31, Jesus tells a story about a rich man who died and went there (however, this was a parable, so whether he meant it literally is up for debate). Tartarus is used only once:
God did not hold back from punishing the angels that sinned, but, by throwing them into Tartarus, delivered them to pits of dense darkness to be reserved for judgment. (2 Peter 2:4)
Note that this is in past tense, and the phrase "reserved for judgment" denotes that that this is not the final fate for the Fallen Angels referred to. Gehenna is a Greek word that when translated means "Valley of Hinnom", which was a trash dump where garbage, filth, corpses of criminals, and the like were burned. Jesus re-purposed this word to refer to the future eventual end and Karmic Death of the wicked. Unfortunately, the King James Version translated ALL FOUR words as "Hell", despite Hades and Gehenna having different meanings and thus causing some confusion, especially considering the KJV's long-standing use and popularity. Recent Bible translations have caught on to this error and make some attempts to correct it, but it's too little, too late to reverse the popular notion of "Hell".
The "fire and brimstone" part comes from a set of passages in chapters 14 and 19-21 of the Book of Revelation, in which the devil and the ungodly are cast into a lake of fire and sulfur, which is generally considered to be the same as Gehenna:
And another angel, a third, followed them, saying in a loud voice: "If anyone worships the wild beast and its image, and receives a mark on his forehead or upon his hand, he will also drink of the wine of the anger of God that is poured out undiluted into the cup of his wrath, and he shall be tormented with fire and sulfur in the sight of the holy angels and in the sight of the Lamb. And the smoke of their torment ascends forever and ever, and day and night they have no rest, those who worship the wild beast and its image, and whoever receives the mark of its name." (Revelation 14:9-11)
And the wild beast was caught, and along with it the false prophet that performed in front of it the signs with which he misled those who received the mark of the wild beast and those who render worship to its image. While still alive, they both were hurled into the fiery lake that burns with sulfur. (Revelation 19:20)
And the Devil who was misleading them was hurled into the lake of fire and sulfur, where both the wild beast and the false prophet already were; and they will be tormented day and night forever and ever. (Revelation 20:10)
And death and Hades were hurled into the lake of fire. This means the second death, the lake of fire. Furthermore, whoever was not found written in the book of life was hurled into the lake of fire. (Revelation 20:14, 15)
"But as for the cowards and those without faith and those who are disgusting in their filth and murderers and fornicators and those practicing spiritism and idolaters and all the liars, their portion will be in the lake that burns with fire and sulfur. This means the second death." (Revelation 21:8)
Note that the first and third passages do mention damned humans. However, none of these passages say anything about being underground or demons doing the tormenting. In addition, Revelation is generally viewed to take place in the future, which some interpret meaning there isn't a "lake of fire" now, or at least nobody is in it yet. There is also the question of how "literal" Revelation is supposed to be interpreted anyway. Annihilationists believe that the torment of the "lake of fire and sulfur" is not literal, but instead figurative or symbolic; the "lake of fire and sulfur" represents eternal destruction and those sent there are completely obliterated, since eternal punishment would instantly mean that God Is Evil.
The more popular notion of Fire and Brimstone Hell where demons torment the damned appears to have originated with Dante's Inferno, so this is Older Than Print... more or less. Most of the layers of Hell in Inferno were more like the Ironic Hell. Only about one or two layers were truly Fire and Brimstone (In fact, the lowest level, reserved for traitors, was completely frozen over).
For the curious, brimstone is another word for sulfur and means "burning stone". It burns quite hot with a blue flame and is more or less unquenchable. It produces sulfur dioxide, which is quite noxious. All in all, it's an unpleasant sort of fire, one that historically was used to purify homes of bad air. Thus its purpose in hell is twofold: it cleans as it burns.
It should perhaps also be noted that Fire and Brimstone Hell is not a uniquely Christian concept. For example, there are a number of passages in The Qur'an that affirms its existence just as vigorously as (and much more graphically than) any of the Bible bits quoted in this article. A couple of examples:
Lo! Those who disbelieve Our revelations, We shall expose them to the Fire. As often as their skins are consumed We shall exchange them for fresh skins that they may taste the torment.—Surah 4:56, "The Women"
But as for those who disbelieve, garments of fire will be cut out for them; boiling fluid will be poured down on their heads, Whereby that which is in their bellies, and their skins too, will be melted; And for them are hooked rods of iron. Whenever, in their anguish, they would go forth from thence they are driven back therein and (it is said unto them): Taste the doom of burning.—Surah 22:19-22, "The Pilgrimage"