Jude 21 Keep yourselves in the love of God, looking for the mercy of our Lord Jesus Christ unto eternal life. 22 And of some have compassion, making a difference: 23 And others save with fear, pulling them out of the fire; hating even the garment spotted by the flesh.
Much of this web ministry is devoted to demolishing enemy strongholds. This is done by taking up the sword of the Spirit, which is the Word of God (Ephesians 6:17).
Quick aside, Lordship salvation is false (salvation by works/holiness). Sheepdog message does not teach that the Christ believer will never sin again or else. When one is translated into the family of Christ, the unrepentant sinner becomes a new creation (2 Cor 5:17) and sinner who has accepted and is covered by the blood of Christ (Isaiah 1:18 and more).
If our salvation is eternally secure, why does the Bible warn so strongly against apostasy? Got Questions? Ministries
Death and hell are associated together. In NASB, ESV, and NIV the word Hell is given as Hades. NLT calls it the Grave. 
Revelation 6:8 And I looked, and behold a pale horse: and his name that sat on him was Death, and Hell followed with him. And power was given unto them over the fourth part of the earth, to kill with sword, and with hunger, and with death, and with the beasts of the earth.
Revelation 20:14 And death and hell were cast into the lake of fire. This is the second death.
Many of the strongest hellfire verses are from the spoken words of Jesus during his earthly ministry.
If you love the lies and worship the devilish deceptions, choosing willfully to hate God and be enemies of God even unto the death, then I say may God have mercy on your soul. The question is asked, who is the world's most persecuted minority?  If you go with numbers and data (evidence) rather than emotion, despite the protests of liberal Christianity and Islamophobia hoaxers/industry, the answer is that Christians are the world's most persecuted minority. I am not complaining I am just calling it how it is.
Of course, the radical leftist would argue that this is fair, that Christ believers such as centuries of Arab Christians should simply be forced to convert to Islam, which is akin to blaming the victim of massive and historical ethnoreligious violence, that they need to make more apologies and appeasing concessions.
What I am saying that it is evil to love the lies, to call deceit truth and evil good. The verse reference there is Isaiah 5:20 Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter!
I will focus on the science non-fiction and accurate foreknowledge aspects for this subject matter. To do that I will lay out a many verses and let the Word speaks for itself. There is decent commentary to be added, things like why is it a bottomless pit, how we know that this ancient literature was vastly far ahead of its time. We have many brave Christ believers who are prepared and spiritually preparing, armoring themselves in the Lord and the Word, to give a strong testimony unto the death. Western politicians and political lawyers, with their words and actions; rhetoric and record, they are leading their countrymen to hell and hell on earth.
The good news (gospel) is that this will become increasingly clear and if you are reading this then there is still time and grace available, it will become even more obvious as the radical leftists move into the dangerous, murderous phase of their revolution. Many of them can't even see that they are being played and worked as fools by foreign money and multinational corporate power.
Aside: I like how this guy  rolls, to be honest. he uses the scorching (but fair) rhetoric, often I use the scorching rhetoric as well.
Genesis 19:28 And he looked toward Sodom and Gomorrah, and toward all the land of the plain, and beheld, and, lo, the smoke of the country went up as the smoke of a furnace. 
Deuteronomy 32:22 For a fire is kindled in mine anger, and shall burn unto the lowest hell, and shall consume the earth with her increase, and set on fire the foundations of the mountains.
Isaiah 14:15 [prophesying against Satan] Yet thou shalt be brought down to hell, to the sides of the pit.
Isaiah 34:8 For it is the day of the Lord's vengeance, and the year of recompences for the controversy of Zion.
9 And the streams thereof shall be turned into pitch, and the dust thereof into brimstone, and the land thereof shall become burning pitch.
(This language is very similar to, and describes the effects of an oil well fire.)
10 It shall not be quenched night nor day; the smoke thereof shall go up for ever: from generation to generation it shall lie waste; none shall pass through it for ever and ever.
Why is it a bottomless pit? That is complicated but the short of it is that, because gravity and oscillation/gyration, you will never hit bottom.
Matthew 5:22 But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire.
Matthew 25:41 Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels:
My guess is that the eternal worm is the eternal psyche or consciousness. This is consistent with the Michael Pearl video note, and Got ?s link.
Mark 9:44 Where their worm dieth not, and the fire is not quenched.
Isaiah 66:24 And they shall go forth, and look upon the carcases of the men that have transgressed against me: for their worm shall not die, neither shall their fire be quenched; and they shall be an abhorring unto all flesh.
Revelation 9:2 And he opened the bottomless pit; and there arose a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.
Revelation 20:10 And the devil that deceived them was cast into the lake of fire and brimstone, where the beast and the false prophet are, and shall be tormented day and night for ever and ever.
Job 33:27 He looketh upon men, and if any say, I have sinned, and perverted that which was right, and it profited me not;
Job 33:28 He will deliver his soul from going into the pit, and his life shall see the light.
testimony unto the death
Proverbs 8:36 But he that sinneth against me [God] wrongeth his own soul: all they that hate me love death.
Daniel 7:25 And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time.
Revelation 12:11 And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
19 There was a certain rich man, which was clothed in purple and fine linen, and fared sumptuously every day:
20 And there was a certain beggar named Lazarus, which was laid at his gate, full of sores,
21 And desiring to be fed with the crumbs which fell from the rich man's table: moreover the dogs came and licked his sores.
22 And it came to pass, that the beggar died, and was carried by the angels into Abraham's bosom: the rich man also died, and was buried;
23 And in hell he lift up his eyes, being in torments, and seeth Abraham afar off, and Lazarus in his bosom.
24 And he cried and said, Father Abraham, have mercy on me, and send Lazarus, that he may dip the tip of his finger in water, and cool my tongue; for I am tormented in this flame.
25 But Abraham said, Son, remember that thou in thy lifetime receivedst thy good things, and likewise Lazarus evil things: but now he is comforted, and thou art tormented.
26 And beside all this, between us and you there is a great gulf fixed: so that they which would pass from hence to you cannot; neither can they pass to us, that would come from thence.
27 Then he said, I pray thee therefore, father, that thou wouldest send him to my father's house:
28 For I have five brethren; that he may testify unto them, lest they also come into this place of torment.
29 Abraham saith unto him, They have Moses and the prophets; let them hear them.
30 And he said, Nay, father Abraham: but if one went unto them from the dead, they will repent.
31 And he said unto him, If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.
There are Christians who have a tough time with the accurate teaching on hellfire . The younger you are in physical age and/or Christ belief; this is an understandable difficulty. I think I read somewhere that only about 1% of those with Christian identity adopt a position such as annihilation or universalism.
Doesn't our sense of justice demand that hellfire exist for some people, such as Hitler and Stalin (read more: atheistic mass murder) to name only the two most obvious examples? Ecclesiastes 3:11 states that God has set eternity in the hearts of humankind. I believe that we also have an innate sense of morality and justice. We know instinctively that something is wrong when we don't want it done to us, that is an easy acid test to apply to questions of "is it evil?"
Two good posts that expose some issues with false teaching and hell tourism.  ; 2 Peter 3:16 As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction.
There are degrees of punishment in hell J. Warner Wallace 5/29/2014
William Lane Craig v. Ray Bradley debate transcript 1994