Since repentance is a decisive human decision to return from wrongdoing, to keep away from evil and depravity and to return to the life of uprightness and obedience, and since its practical consequences are serious in man's life and his destination, repentance is an obligatory duty for every disobedient, criminal and deviated one on the basis of reason and the understanding of the danger of wrongdoing and the harm of deviation and crime.
Both deviation and wrongdoing are dangerous for the life of mankind and cause harm to its benefits of social life; the transgression of the guilty and the criminals against the life system, the exceeding the principles of morals and right behaviour, the threatening the security of mankind and their living and exposing its life to danger.
Through deviation and disobedience man exposes himself to Allah's wrath and, thus, he sells his happiness for pain and torment and ends his life with a sorrowful and dreadful.
Therefore, the disobedient one not only loses both the present life and the hereafter but also causes harm both to himself and to others.
No wise man desires such a disastrous result to occur to himself or is pleased with it, without striving to refuse and change it.
That is why repentance is obligatory for every Muslim and every human on the basis of reason and the comprehension of human interests.
The judgement of the reason for the necessity of repentance coincides with the laws of the Divine Religions, altogether. It purifies man from sins, liberates him from the mazes of deviation and evil and calls him to a life of purity and righteousness. Starting from the principles, Islam considers repentance among its main pillars and a decisive step towards the way of salvation and guidance for the whole of mankind.
Thus, the Holy Qur'an and the Prophet's traditions (Sunnah) focuses on the necessity of repentance and the return to Allah, opening a new page in man's record; turning away from the detestable past which is full of rebellious deeds, and which blackens the clear pages by guilty acts and corrupted the beautiful life with the stamp of shame.
So the Holy Qur'an has always taken a firm stance against the disobedient and declared its forgiveness by opening the door of Divine repentance and forgiveness to them. Thus, the Holy Qur'an addresses them:
“... and turn to Allah all of you, O believers, so that you may be successful.” (Holy Qur’an, 24:31)
“... He brought you forth from the earth and made you dwell in it, so ask forgiveness of Him, then turn to Him. Surely my Lord is Nigh, Answering.” (Holy Qur’an, 11:61)
“O you who believe, turn to Allah with sincere repentance ...” (Holy Qur’an, 66:8)
Consequently, it becomes man's duty to respond to this Divine call and make use of this unique opportunity before the Day of Regret and Remorse in which man will say:
“... O woe is me, that I fell short of my duty to Allah; and surely I was of those who laughed to scorn.” (Holy Qur’an, 39:56)“... O woe is me, that I fell short of my duty to Allah; and surely I was of those who laughed to scorn.” (Holy Qur’an, 39:56)