Wa `alaykum as-salamu wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Thank you for your question.
In fact, sincere repentance erases and wipes away all sins. So, it’s never too late for a Muslim to repent and be back to the true path of Islam. Prophet Muhammad (peace be on him) told us that one who repents sincerely to Allah from his sins will be like the one who never commits any sins. He (peace be on him) said, “One who has repented of a sin (sincerely) is like one who has never sinned at all.” (Ibn Majah)
If one commits wrongdoings but repents sincerely, and changes his or her life around for better, then Allah certainly promises to grant him or her mercy and forgiveness. It is one of the basic principles of belief in Islam that Allah is All-Forgiving and All-Merciful.
Here are a few verses which clearly convey this crucial concept:
“Do they not know that it is Allah Who accepts the repentance of His servants and receives (approves) their charity, and that Allah is the Relenting, the Compassionate?” (At-Tawbah 9: 104)
“Say: ‘O My servants who wronged against their souls, do not despair of Allah’s mercy! For Allah forgives all sins; for He is indeed Forgiving, Compassionate.” (Az-Zumar 39:53)
A Muslim, therefore, should not put off repentance. He or she has to take the necessary steps immediately, for no one can tell when the death will overtake us. The door of repentance is wide open so long as we are not in the throes of death, for the Prophet (peace and blessings be upon him) said, “Allah accepts the repentance of His servant so long as death has not reached his collar bone.” (At-Tirmidhi)
But since we have no way of knowing when death will overtake us, we must never be complacent or slack in hastening to taking steps towards repentance.
While speaking of repentance, we must rush to add, that it cannot be considered as valid unless one takes the following steps:
a) One must feel deep remorse for the sins one has committed.
b) One must refrain from committing such a sin totally while also abstaining from all those leads or circumstances that led him or her to such a sin in the first place.
c) He or she must be firmly resolved never to sin again, and immediately becoming occupied in whatever good deeds that he can in order to wipe out his or her past sins.
d) And, if the sin committed is against someone else, one has to correct his or her mistake.
May Allah guide you and us all to the best in this world and the world to come.
May Allah accept your and our good deeds!
Allah Almighty knows best.