Repentance means turning back from disobeying Allah to obeying Him.
Repentance is beloved to Allah, as He says:
“Verily, Allah loves those who repent and those who purify themselves.” [Al-Qur’an 2:222]
Repentance is an obligation on every believer. Allah says:
“O you who believe! Turn to Allah in sincere repentance!” [Al-Qur’an 66:8]
Repentance is from the means of attaining success. Allah says:
“And O believers, all of you, repent to Allah in order that you may be successful.” [Al-Qur’an24:31]
Success is when someone gets what he is looking for and is saved from what he is running from.
Through sincere repentance Allah forgives sins no matter how big they are and no matter how many they are. Allah says:
“Say: O My slaves who have transgressed against themselves (because of sins), do not despair from the mercy of Allah. Verily, Allah forgives all sins. Verily, He is All-Forgiving, Most Merciful.”
O my brother who has fallen into sins, do not despair from the mercy of your Lord, for indeed the door to repentance is open until the sun rises from the west. The Prophet sallallahu ‘alayhi wa sallam said, “Verily, Allah extends His hand out at night in order to accept the repentance of the sinner by day. And He extends His hand out during the day in order to accept the repentance of the sinner by night, until (the day) when the Sun will rise from its West.” [Reported by Muslim]
And how many people have repented to Allah from numerous and enormous sins and Allah has accepted their repentance? Allah says:
“And those who do not supplicate to another god along with Allah, nor do they kill a person that Allah has made forbidden (to kill) except with just cause, nor do they commit fornication. And whoever does this shall receive the punishment. The torment will be doubled for him on the Day of Resurrection and he will abide therein in disgrace. Except those who repent and believe and do righteous deeds, for those, Allah will change their sins into good deeds. And Allah is Most Forgiving, Most Merciful.”
Sincere repentance must meet five conditions (in order to be accepted), which are:
Sincerity to Allah, the Most High: This is by the person doing it only for the sake of Allah and seeking His reward and salvation from His punishment.
Remorse: for the sin that was committed, such that he is sad he did it and wishes he had never done it.
Ceasing: to commit the sin immediately. If the sin was against Allah, then he should a) stop doing it if it was an unlawful act, or b) hasten to do it if it was an obligation that he abandoned doing. And if the sin was against a created being (such as humans), then he should hasten to free himself from it, whether by returning it back to him or seeking his forgiveness and pardon.
Determination: to not go back to doing that sin again in the future.
The repentance should not occur before the time when its acceptance is terminated, either by death or by the sun rising from the west. Allah says (in a hadith qudsi), “Repentance is of no effect for those who commit sins constantly until when death faces one of them, he says: Verily I repent now.” The Prophet sallallahu ‘alayhi wa sallam said, “Whoever repents before the sun rises from its west, Allah will accept his repentance.” [Reported by Muslim]
O Allah, grant us the sincere repentance and accept it from us, verily You are the All-Hearing, the All-Knowing.