There are many ways to understand about the true essence of heaven and hell and the necessity of their existence. In order to have a better understanding of the Issue we will explain some of these ways:
First: Allah's justice
Allah has created human beings with free will in order to have a choice in following the right wrong or path. We also believe that not everyone gets their reward or punishment entirely and the way they should in this world. Therefore if there was no world after this world for people to see the complete outcomes of their deeds, this would contradict Allah's Justice. Needless to say that Allah does not do any act without using his wisdom. Since this world does not have the potential to pay the whole reward for good and whole punishment for bad, there should be a day that everyone will be rewarded or punished for their deeds entirely.
Second: Allah's wisdom and mercy
The wisdom of Allah also calls for a life in the hereafter for all humans. Because Allah does not do any aimless actions, the reason behind the creation of human beings is for humans to reach their spiritual perfection through their free will and this is not reachable without the existence of another world.
Third: The Fetrah (Human nature) and its desire for an everlasting life
There is an indisputable desire in all humans to be everlasting and fulfilling this desire is only possible in a world other than the one we live in.
All discussion about resurrection ultimately comes down to there being a heaven and hell. Heaven is the center of all grace and spiritual and physical blessings, while Hell is the center of deprivation and hardship, the place where Satan and his followers will be punished in. According to Quranic verses and ahadith, heaven and hell are two certain realities and those who doubt in there existence ( of course after hearing the appropriate reasoning that proves them) or think of them as mere myths will soon confront the truth about them (in the hereafter).
Not only heaven and hell are two shaking realities that will be seen in the hereafter, but moreover their existence even at this moment has been proven through logical reasoning and Islamic tradition.
Before discussing the issue of heaven and hell we must explain and bring the reasoning that proves the existence of "Ma'ad". The word Ma'ad is derived from the root word of "Awd" which means returning. In Islamic terms, it refers to the returning of people’s souls to their bodies on the Day of Judgment. Believing in Resurrection is not confined to Islam and is taught by all holy religions. After calling their followers to Monotheism, all prophets have taught to believe in the Day of Resurrection and have underlined the importance of such a belief.
Islam, the most comprehensive religion handed down to mankind, views the belief in resurrection as one of the fundamentals of religion, therefore believing in it is one of the conditions of being a Muslim.
One sixth of the Quran's verses pertain to the issues that revolve around this incident. Issues like Barzakh, the Day of Resurrection, Mizan (the scale by which the deeds of humans will be evaluated on the Day of Resurrection), Heaven and Hell.
The logical reasoning that proves "Ma’ad" is as follows:
First: Allah's Justice
As we all know, the human being is the only creature that has been created with free will, and due to this god given gift he is able to make choices of his own. He can choose to be a good and obedient servant of Allah, respect the rights of the poor and the helpless while he can also disobey Allah and ignore his commands. One who chooses the latter will end up warring and opposing the prophets of Allah.
We know for sure that there will come a day for all people to experience death and return to Allah. If death comes when a believer has not received his rewards and a disbeliever hasn't been punished for his bad deeds, and if there is no life after this one for such to take place there, then how can we justify Allah's justice?
Obviously this contradicts Allah's justice. Therefore due to the fact that this world doesn’t bear the capacity for giving the believer his reward wholly and giving a disbeliever his whole punishment, there should be a day in which everyone will receive their punishment or reward the way they should. In this regard Allah says in the Quran: "Shall we treat the God wary like the corrupt?" Surely such a thing is not true. Instead, everyone will be dealt with justly and this necessitates the need for the Day of Judgment; the day in which all of this will be accomplished.
Second: The Wisdom and Mercy of Allah
The wisdom of Allah calls for death not being the end of our lives forever and if it was to be such, Allah's act would be similar to that of one who creates valuable things and at the end simply destroys them. This would clearly contradict the wisdom of the Almighty.
Does it make sense for Allah that has created man and set him on a journey to take away his soul and end everything just at that? Does every thing end with our death in this world? In this case will the creation of human beings and this world be something done out of wisdom? What is consistent with the wisdom of Allah is to give humans the chance to fulfill all spiritual needs they have been created for. There is no doubt that the creation of this world was not aimless and Allah has not created this world for no reason. Therefore knowing that Allah does not act in vain, there should be a day in which the purpose of this world is fulfilled. On the other hand Allah's mercy calls for him to give human beings the chance to reach their perfection, so there must be another world that humans can reach their perfection in.
Third: The Desire for an everlasting life
The desire for being eternal is an intuitive one. All people like to live and not have their lives end with death. It is because of this that the ultimate aim of the creation of man isn't physical pleasures, because even when reaching these pleasures, he isn't completely satisfied and is looking for more. This is by virtue of the nature Allah has created him with; man is always seeking perfection and highness. After achieving different ranks in this world, he looks to the next to quench the thirst for perfection, thus actualizing his potentials and returning to his origin which is Allah (swt).
The intuitiveness of the desire for eternity explains why many people are in fear of dying. What is ironic is that on one hand, people dislike and are fearful of death, while on the other hand, they long for eternal life.
All of the needs our fitrah or nature has are in order for him to reach perfection and each have a reason. This reason is a sign that there is another world to come, because this world in no way deserves to be lived in forever. The fear of death and what it has entailed throughout history is great evidence that shows the wish for an everlasting life is a fitri need of us humans. Knowing that such a desire can not be fulfilled in this world, it can only be fulfilled through "Ma'ad" and life in the hereafter.
Now that we have explained the reasoning behind the belief in "Ma'ad" and how it is related to our Fitrah we must add that all discussions which revolve around Ma'ad result in explaining the two issues of Heaven and Hell.
Regarding Heaven and Hell and their essence one must say that Heaven is the center of all spiritual and physical blessings. Heaven has been promised to the righteous and will be a place of complete prosperity and salvation.
Several verses in the Quran speak of heaven. In the Quran the Almighty says: "Indeed the God wary will be in a secure place", "For them shall be the abode of peace near their Lord", "…reclining therein on couches. They will find in it neither any [scorching] sun, nor any [biting] cold", "and a paradise as vast as the heavens and the earth, prepared for the God wary".
The same way that Allah has created heaven for the righteous and pious, he has also created Hell for the disbelievers and sinners. Hell is the center of all deprivations and pains and Allah has promised that Satan and his followers will be punished in it. In the Quran Allah says: "I will surely fill hell with you and all of those who follow you", "and indeed hell is the promised place of them all".
Taking the reasons we explained into consideration there remains no doubt about the fact that the destiny of all humans will either be heaven or hell. Heaven and hell are for real and moreover, their existence at this very moment and before the Day of Resurrection has been proven through logical reasoning and Islamic tradition. Those who dispute the existence of heaven and hell (of course after hearing the reasoning that proves them) or think of them as myths will soon understand the truth about them in the hereafter.
1- The connection between our acts and heaven, Question 1801 (website: ).
2- Resurrection and eternity, Question 1151 (website: ).
3- Resurrection and “The Day of Regret”, Question 1496 (website: ).
 Al-Munjid, pg. 536.
 (اَمْ نَجْعَلُ الْمُتَّقینَ کَالْفُجّارِ) Sad:28.
 Mabda’ and Ma’ad by the center for Islamic Studies of Sepah, the chapter on Ma’and.
 Javadi Amoli, Abdullah, Yade Ma’ad, pp. 108-109.
 Ja’far Sobhani, Al-Ilahiyyat ala Hudal-Kitabi wal-Sunnati wal-Aql, pp. 176-177.
 Ashtiyani, Seyyid Jalaluddin, Ma’rifatul-Ma’ad, pg. 26.
 Rabbani, Muhammad Reza, Ma’ade Rabbani, pg. 129.
 Adopted from Question 125 (website: ) The logical and fitri reasons for Ma’ad. For further information on Resurrection and the references that enlarge on it, refer to the subject mentioned.
 (اِنَّ الْمُتَّقینَ فى مَقامٍ اَمینٍ) Dukhan:51.
 Anaam:127 (لَهُمْ دارُ السَّلامِ عِنْدَ رَبِّهِمْ)
( لایَرَوْنَ فیها شَمْسا وَ لازَمْهَریرا) Insan:13.
 (وَ جَنَّةٍ عَرْضُهَا السَّماواتُ وَ الاَْرْضُ اُعِدَّتْ لِلْمُتَّقینَ) Ale-Imran:133.
 (لَاءَمْلَئَنَّ جَهَنَّمَ مِنْکَ وَ مِمَّنْ تَبِعَکَ مِنْهُمْ اَجْمَعینَ) Sad: 85.
 (وَ اِنَّ جَهَنَّمَ لَمَوْعِدُهُمْ اَجْمَعینَ) Hijr:43.
 (وَعدَاللهِ، لاَ یُخلِفُ اللهُ المیعاد) Zumar:20.
 Haravi says to Imam Reza: "Tell me about heaven and hell and whether or not they have already been created". The Imam replied: "Yes (they have been created), When the prophet of Allah ascended in to the skies (on a journey known as Me'raj) he entered heaven and also saw the fire (of hell). Haravi then extends saying: "What is the status of one who denies that they exist at the very moment?" the Imam answered: "He has denied the prophet and has no share of our wilayah (the household of the prophet) and …. And will stay in hell forever. Allah says in the Quran ' This is the hell which the guilty would deny! They shall circuit between it and boiling hot water' (Al Rahman 34-33)"; " أَخْبِرْنِی عَنِ الْجَنَّةِ وَ النَّارِ أَهُمَا الْیَوْمَ مَخْلُوقَتَانِ فَقَالَ نَعَمْ " … Biharul-Anwar, vol. 8, pg. 284.
For further information, see: The existence of Heaven and Hell at the very moment, Question 101 (website: 1798).