Why the verses of punishment in the Holy Quran
In Islam human are not angels...This sentence actually has two meanings one that humans are not perfect and that is the obvious one, the other is that humans have to choose what they believe in. GOD, the most merciful, did not leave us unarmed, HE gave us the mind and our conscience which are our guiding compasses in our choice.
Islam understands human nature very well, consequently throughout the Holy Quran and the sayings of Prophet Muhammad the concept of "the doors of forgiveness are ALWAYS open" is often stressed and emphasized. In the Holy Quran GOD says: "But indeed, I am the Perpetual Forgiver of whoever repents and believes and does righteousness and then continues in guidance." (20:82)
Abu Hurairah, May Allah be pleased with him, reported that Prophet Muhammad, peace and blessings be upon him, said: " Allah has one hundred mercies, out of which He has sent down only one for jinn, mankind, animals and insects, through which they love one another and have compassion for one another; and through it, wild animals care for their young. Allah has retained ninety-nine mercies to deal kindly with His slaves on the Day of Resurrection." [Al-Bukhari and Muslim]. (Riyad as-Salihin, The Book of Miscellany, Book 1, Hadith 420)
Abu Hurairah, May Allah be pleased with him, also reported that Prophet Muhammad, peace and blessings be upon him, said, "By the One in Whose Hand my soul is, were you not to commit sins, Allah would replace you with a people who would commit sins and then seek forgiveness from Allah; and Allah would forgive them".[Muslim]. (Riyad as-Salihin, The Book of Miscellany, Book 1, Hadith 422)
This deep understanding of human nature must also be accompanied by the threat of punishment. Human nature varies a lot, some are conscientious by nature of course, but some others need the threat of punishment to make them think twice before they commit a sin.
1- Punishment proves freedom of choice
" There is no compulsion in religion" (2:256) this is one of the fundamental concepts in Islam. But freedom of choice has a very expensive price that is , you are responsible for the consequences of your choice. Responsibility for your choice is the biggest proof that you HAVE A CHOICE...
If punishing and torture were the targets then why would GOD send HIS messengers? Why will GOD command Muslims to respect the others and guarantee their religious freedom? Remember that Showing you the consequences of your choice is the biggest proof that you actually DO have a choice and that NOONE is allowed to oblige you to a certain path or else the whole idea about hell and heaven is not valid.
There is hell and there is heaven because you have a choice and they are both results of that choice...the messengers were sent by GOD to remind people of what they keep trying to forget, that they are responsible for their choice and they have to accept the consequences of their choice. If you do not have a choice in your belief then you don't need a compass (brain) or a guide (GOD's Messengers, peace and blessings be upon them) or even books (Holy books) to remind you of your options.
The main idea why we have religions is that we are FREE TO CHOOSE, otherwise if we are like the angels, who were created already believing in God , then we will not need Prophets or Holy books or heaven or hell or ANY guidance because we are walking a one way path with no options so there will be no point in all that.
But this is not the case, we have a choice, so we make choices and accept their consequences. And, as you would have done with your own beloved sons or daughters, if you choose to be good then you will be rewarded if you choose to be bad you will be punished and both rewards and punishments are made crystal clear to you.
In the Holy Quran God says: "[He] who created death and life to test you [as to] which of you is best in deed – and He is the Exalted in Might, the Forgiving –," (67:2)
2- Punishment is one of the pillars that keep the society intact and help us feel safe. Imagine a world where no one is punished, no one pays for the pain he inflicts on others...Is that a world you want to live in? I have seen the trailer of a horror movie before called "The Purge", the main idea of which was that the government decided that people will have 24 hours without punishment for anything they commit...of course this is a horror movie, but it also shows that not everyone is peaceful and righteous, some would like to inflict pain or transgress and the only thing between those people and committing what they want is the fear of punishment. In Arabic we say: "The one who is safe of punishment will misbehave".
In the Holy Quran God says: "They have an awning of fire above them and beneath them a dais (of fire). With this doth Allah appal His bondmen. O My bondmen, therefore fear Me!" (39:16)
In another verse HE says: "On the Day when every soul will find itself confronted with all that it hath done of good and all that it hath done of evil (every soul) will long that there might be a mighty space of distance between it and that (evil). Allah biddeth you beware of Him. And Allah is Full of Pity for (His) bondmen." (3:30)
3- Punishment also acts as way to reassure the righteous that he is on the right path. When you see someone being punished for something you committed this reassures you that you were right not to do a similar act.
4- Punishment is a comfort for the one victimized by the sinner. If someone steals your car, surely when he is punished you feel better.
5- Punishment is a educational tool, if you see someone punished for something you sure will think twice before doing the same thing. So the concept of punishment is not 'bad' actually it is essential, but the idea here is how to guarantee that this punishment is successful.