HELL FIRE EXISTS:
When Allah (subhanu wa ta’ala) created Universe, He created Paradise and Hell. They will never come to an end or cease to exist. Allah (subhanu wa ta’ala) created Paradise and Hell before the rest of creation, and He created inhabitants for each of them.
Allah (subhanu wa ta’ala) says in Quran:
About Paradise: “...for Paradise as wide as are the heavens and the earth, prepared for al-Muttaqun” (3:133)
About Hell-fire: “And fear the fire, which is prepared for the disbelievers” (3:131)
The Prophet (salAllahu `alaihi wa sallam) said: “When Allah (subhanu wa ta’ala) created Paradise and Hell, He sent Jibreel to Paradise, saying “Go and look at it and at what I have prepared therein for its inhabitants”. So he went and looked at it and at what Allah had prepared therein for its inhabitants.... then He sent him to Hellfire saying, “Go and look at it and what I have prepared therein for its inhabitants”, so he looked at it and saw that it was in layers, one above the other....” [Muslim, Abu Dawood]
Allah’s Apostle (salAllahu `alaihi wa sallam) also said, “When the month of Ramadan starts, the gates of the heaven are opened and the gates of Hell are closed and the devils are chained.” [Sahih Al-Bukhari]
WHEN PEOPLE DIE THEY KNOW WHERE THEY ARE GOING:
Messenger of Allah (salAllahu `alaihi wa sallam) said, “When anyone of you dies, he will be shown his position morning and evening. If he is one of the people of Paradise then he will be one of the people of Paradise, and if he is one of the people of Hell, then he will be one of the people of Hell, and he will be told, “This is your position, until Allah (subhanu wa ta’ala) resurrects you on the Day of Resurrection”. [Sahih Muslim, al-Bukhari]
* Everyone has a position in Hell and a position in Paradise. In the grave, the angels tell a person going to Paradise, ‘This had been your abode, had you done evil but look at your right side,’ and the person will see a window opening to Paradise. Opposite is true for a disbeliever.
That’s why, the Prophet (salAllahu `alaihi wa sallam) said: "No one dies except that he knows whether he is going to be in Hell or Heaven."
HOW DOES A PERSON KNOW THAT?
Some scholars say that you already know that because of your deeds.
Other scholars say that the Angel of Death tells you where you are going.
RASOOL-ALLAH SAW HELL-FIRE IN HIS LIFE:
No one among the common people has ever seen Hell-fire. The Prophet Muhammad (salAllahu `alaihi wa sallam) was shown it in Isra’ wa al-Mi'raaj. Other proof of Prophet seeing Hell-fire (and Paradise) is several, including this Hadith that Prophet said after prayer: “Paradise and Hell were shown to me. Paradise was brought close to me, so that I tried to take fruit from it but I could not reach it. Hell was shown to me, and was brought so close that I stepped back for fear that it would touch me.” (Sahih al-Jaami’)
DESCRIPTION OF HELL-FIRE:
In Isra’ wa al-Mi'raaj, the Prophet (salAllahu `alaihi wa sallam) traveled from Mecca to Jerusalem and from Jerusalem to the Heavens. Over there he saw Paradise and Hell along with meeting earlier Prophets of Allah (peace be upon them).
THE GUARDIANS OF HELL-FIRE:
The guardians of the Hell-fire are 19 angels. Allah (subhanu wa ta’ala) says: “Soon I will cast him into Hellfire. And what will explain to you what Hellfire is? Naught does it permit to endure, and naught does it leave alone! Darkening and changing the color of man! Over it are nineteen [angels as guardians and keepers of Hell]” (74:26-30)
The number was mentioned only to create test for the disbelievers who thought that they could easily overcome such a small number. They thought they would be able to fight them and kill them and then run away from Hell-fire. However, we know that angels are not like human beings. Disbelievers of Mecca underestimated the abilities of the angels. Jibril has six hundred wings and one angel can flip the Earth on its one wing (by the will of Allah) as we know from the story of the Prophet Lut (’alayhis salaam). Allah (subhanu wa ta’ala) says: “And We have set none but angels as guardians of the Fire, and We have fixed their numbers  only as a trial for the disbelievers..” (74:31)
Maalik is the name of the angel who is the in charge of Hell-fire.
THE ENORMITY OF HELL-FIRE:
In basic terms, the area of Hell-fire to torture just one disbeliever will be equivalent to a couple of football fields!
Hell-fire is huge!
1- Some companions were sitting with the Messenger of Allah (salAllahu `alaihi wa sallam) and they heard the sound of something falling. The Prophet (salAllahu `alaihi wa sallam) said, “Do you know what that was?” We said, “Allah and His Messenger know best”.
He said, “That was a stone that was thrown into Hell seventy years ago and it was falling through Hell until now”. (Muslim)
*Here we should remember that 70 years of Allah are equivalent to approximately 70,000 of our calendar.
2- Those who will enter Hell will be many, and one of them will be so huge that his molars will be as big as Mount Uhud, and the distance between his shoulders will be equivalent to three days walking. Nevertheless, Hell will accommodate the huge number of evildoers who have existed throughout history, in spite of their huge size, and there will still be room for more, as Allah (subhanu wa ta’ala) says in the Quran:
“On the Day when We will say to Hell: “Are you filled?” It will say: “Are there any more to come?” (50:30)
3- The Prophet (salAllahu `alaihi wa sallam) said, “Hell will be brought forth that Day by means of seventy thousand ropes, each of which will be held by seventy thousand angels.” (Muslim)
We can only image the vastness of this terrifying creation that requires such a huge number of strong and powerful angels whose strength is known only to Allah (subhanu wa ta’ala)!
4- The sun and the moon will be like tiny stones in Hell-fire. The Prophet (salAllahu `alaihi wa sallam) said:
THE LEVELS OF HELL:
While the levels of Paradise are called darjaat, the levels of Hell-fire are called darkaat.
The hypocrites will be in the lowest depth which will be the worst abode and greater in the intensity of heat. Allah (subhanu wa ta’ala) says in the Quran: “Verily the hypocrites will be in the lowest depths [grade] of the Fire"(4:145)
Abu Talib will be in the highest level (which will be the lowest in punishment) of Hell-fire: The Prophet (salAllahu `alaihi wa sallam) said about him, “He is in a shallow fire, if it had not been for me he would have been in the bottom of the (Hell) Fire.” [Sahih Al-Bukhari]
However, this will be not satisfying either because the Prophet (salAllahu `alaihi wa sallam) said: “The person who will have the least punishment from amongst the Hell Fire people on the Day of Resurrection, will be a man under whose arch of the feet a smoldering ember will be placed so that his brain will boil because of it.” [Sahih al-Bukhari]
THE DOORS OF HELL-FIRE:
The Hell-fire has 7 doors and Paradise has 8 doors. Allah (subhanu wa ta’ala) says “And surely, Hell is the promised place for them all. It has seven doors, for each of these doors is a [special] class [of sinners] assigned”. (15:43-44)
FUEL OF HELL FIRE:
There is always something that is needed to keep the fire going. The fire is destructive in its nature, so it needs to consume something to keep itself going. The fuel of the Hell-fire will be Kuffaar as Allah (subhanu wa ta’ala) says: “… then fear the Fire [hell] whose fuel is men and stones, prepared for the disbelievers” (2:24)
The Kuffaar, their idols and the stones will keep fire going. The fire will consume the skin and flesh of its inhabitants, but with the Will of Allah, their skin and flesh will
The disbelievers in the Hell-fire will be dragged on their faces in humiliation. Allah (subhanu wa ta’ala) says in Quran: “On the day when they are dragged into the Fire upon their faces; taste the touch of Fire. Surely, We have created everything according to a measure” [Surah Al-Qamar: 48]
The Face is a very honorable part of human body. If it is hurt and insulted, it is worse than others parts of the body. Therefore, this would be a great disgrace for those who rejected the signs of Allah (subhanu wa ta’ala) in this life.
Allah says in Surah Al-Waqiyyah: 41-45: "The Companions of the Left Hand-what will be the Companions of the Left Hand? (They will be) in the midst of a fierce Blast of Fire and in Boiling Water. And in the shades of Black Smoke: Nothing (will there be) to refresh nor to please: For that they were wont to be indulged before that in wealth (and luxury)."
The Hell-fire is 70 times hotter than present fire (in the world). Therefore, we cannot even imagine its devastating ability.
The intensely hot winds blow in the hell-fire and are called Samoom.
The super-heated (boiling) water is available in hell-fire to drink and is called Hameem.
The Hell-fire will have shade of smoke and is called Yahmoom.
Ad-Daree' is a thorny plant, which will be the food of the people of Hell and will be of no benefit whatsoever to them, and they will not enjoy it in the least; this is one of the forms of punishment that they will suffer.
Az-Zaqqoom: Allah says: “Verily the tree of Zaqqum will be the food of the sinful, like molten brass, it will boil in their insides, like the boiling of scalding water.” (44:43-46). The Messenger of Allah (salAllahu `alaihi wa sallam) said: “If one drop from Az-Zaqqum were to land on this world, the people of earth and all their means of sustenance would be destroyed. So how must it be for the one who must eat it?” [Tirmidhi]
Al-Ghasleen and al-Ghassaaq [festering pus that oozes out of the skin of the people of Hell]. Allah (subhanu wa ta’ala) says: “So no friend has he here this Day, Nor has he any food except corruption [or filth] from the washing of wounds [al-Ghasleen], which none do eat but those in sin”. (69:35-37)
Al-Muhl: Prophet (salAllahu `alaihi wa sallam) said: “It (al-Muhl) is like boiling oil, and when it is brought near a person’s face, the skin of the face falls off into it.” [Tirmidhi]
The garments of melted copper tar: Allah (subhanu wa ta’ala) says in the Quran: “And you will see the sinners that Day bound together in fetters. Their garments of liquid pitch and their faces covered with Fire”. (14:49-50)
For disbelievers, most torment will be on their faces because that would cause them most humiliation.
People will be chained to add to their agony.
“The molar of the kaafir or the eye-tooth of the kaafir, will be like Uhud, and the thickness of his skin will be like a journey of three (days)”. (Muslim)
“The kaafir’s skin will be forty-two cubits thick and his molar will be like Uhud and the space he occupies will be as wide as the distance between Makkah and Madinah.” (Tirmidhi)
Hell-fire keeps consuming itself because of its destructive nature.
Every time the temperature goes down Allah adds more fire to it.
The effect of Hell-fire is Summer and Winter. The Prophet (salAllahu `alaihi wa sallam) said: “Hell complained to its Rabb, saying “O my Rabb, some parts of me have consumed others.” So He allowed it to exhale twice, once in the winter and once in the summer. That is why you find extreme heat (in the summer) and extreme cold (in the winter)”. [Sahih Bukhari]
Hell-fire sees and speaks. As mentioned in the Quran, it asks for more dwellers. It makes a whizzing sound; Allah (subhanu wa ta’ala) says: “When it sees them from a place far off they will hear its fury and its roaring.” (25:12)
CATEGORIES OF PEOPLE IN HELL-FIRE:
The Disbelievers will not be able to escape from the punishment of Hell-fire.
"Shaytaan will be in the Hell-fire: “He [Shaytaan} only invites his adherents that they may become Companions of the blazing Fire” (35:6)
Among those who are mentioned by name (in authentic traditions) to be in hell are Abu Lahab, ‘Amr Ibn Luhai al-Khuza’i, Fir’aun and others.
The hypocrites will be in the lowest depth as mentioned in Quran.
Confirmation of hell that is based on description includes every unbeliever, polytheist, or hypocrite. Allah (subhanu wa ta’ala) says in the Quran: “And whoever seeks a religion other than Islam, it will not be accepted from him and he will be one of the losers in the Hereafter.” (3:85). These people will abide in hell-fire forever.
People of Hell-fire will also be the Leaders who lead people astray.
The Arrogant: Hell said, “The arrogant and proud will enter me.” [Sahih Muslim] The worst of arrogants are disbelievers whose pride keeps them from accepting the message of Allah, such as in the case of Abu Jahl.
The Muslims whose sins outweigh their good deeds (but the Muslims, if they were sincere, will be able to get out of the Fire by the Mercy of Allah or through the intercessions of the Prophet Mohammad (salAllahu `alaihi wa sallam)).
The punishment of the mushrikeen, tyrants and picture-makers will be severe. Imam Ahmad reports that the Prophet (salAllahu `alaihi wa sallam) said: “On the Day of Resurrection a neck will stretch forth from Hell; it will have two eyes to see, two ears to hear, and a tongue to speak. It will say, “I have been appointed to take care of three types of people: every arrogant tyrant, every person who called on some deity other than Allah and those who made pictures”
A person should never point at someone and say he/she is “doomed to Hell-fire”. This is a matter only in Allah’s hand. We are not supposed to judge who is going to Paradise and who is going to Hell-fire.
The only thing we can say about someone like a tyrant kafir is something like, “If this person continues to spread wickedness and dies on it, he will go to Hell-fire.” And this is only because of Allah’s statement in the Quran that anyone who dies on kufr the curse of Allah, His angels and of the People is on him (as mentioned in Surah Al-Baqrah).
THE LAST ONE AMONG THE PEOPLE OF HELL-FIRE TO ENTER JANNAH:
Reported in Sahih al-Bukhari, the Prophet (salAllahu `alaihi wa sallam) said:
"Some of the people will stay in Hell (be destroyed) because of their (evil) deeds, and some will be cut or torn by the hooks (and fall into Hell) and some will be punished and then relieved. When Allah has finished His Judgments among the people, He will take whomever He will out of Hell through His Mercy.
He will then order the angels to take out of the Fire all those who used to worship none but Allah from among those whom Allah wanted to be merciful to and those who testified (in the world) that none has the right to be worshipped but Allah. The angels will recognize them in the Fire by the marks of prostration (on their foreheads), for the Fire will eat up all the human body except the mark caused by prostration as Allah has forbidden the Fire to eat the mark of prostration. They will come out of the (Hell) Fire, completely burnt and then the water of life will be poured over them and they will grow under it as does a seed that comes in the mud of the torrent.
Then Allah will finish the judgments among the people, and there will remain one man facing the (Hell) Fire and he will be the last person among the people of Hell to enter Paradise."