Forgiveness of Major Sins
Allāh جل وعلا says, “Verily, Allāh forgives not that partners should be set up with Him in worship, but He forgives that (anything else) to whom He pleases” (An-Nisā’ 4: 48).
And in the Hadīth [the Messenger ﷺ said, that Allāh will say,] “Remove from the Fire whosoever has in his heart īmān equivalent to the weight of mustard seed” [Narrated by Abī Sa'īd and reported by Bukhārī & others].
As He says in the Qur'an:
"Do not despair of God's mercy; He will forgive you of all your sins".Qur'an (39:53).
In another verse, Allah says:
"And He wishes to forgive you" Qur'an (4:146).
Abudhar (RZA) narrates that the Prophet (SAW) said: One who uttered (in sincerety) the Kalimah La Ilaha Illallah and died having faith therein, certainly he would enter Jannah. Abudhar says: I asked the Prophet (SAW), even in the person has committed fornication and theft? The Prophet (SAW) responded: yes, though he has committed fornication and theft; (Abudhar says) I said again, even if he has committed fornication and theft? The Prophet (SAW) said: Yes, though he has committed fornication and theft. (Abudhar says) I again asked: Even if he has committed fornication and theft? The Prophet (SAW) said: Yes, even if he has committed fornication and theft on the contrary to the will of Abudhar. (Bukhari: 5827)
The Prophet said, "The one who commits an illegal sexual intercourse is not a believer at the time of committing illegal sexual intercourse and a thief is not a believer at the time of committing theft and a drinker of alcoholic drink is not a believer at the time of drinking. Yet, (the gate of) repentance is open thereafter." (Sahih Al-Bukhari Hadith 8.801 Narrated by Abu Huraira)
Anas Ibn Mâlik رضي الله عنه said: “I heard the Prophet صلى اللهُ عليه وآله وسَلَّم saying: Allah تبارك وتعالى said: O son of Adam! I shall go on forgiving you so long as you pray to Me and aspire for My forgiveness whatever may be your sins. O son of Adam! I do not care even if your sins should pile up to the sky and should you beg pardon of Me, I would forgive you. O son of Adam! If you come to Me with an earthful of sins and meet Me, not associating anything with Me in worship, I will certainly grant you as much pardon as will fill the earth”.
The Prophet صلى اللهُ عليه وآله وسَلَّم : “By Him in Whose Hand is my life, if you were not to commit sin, Allah would sweep you out of existence and He would replace (you by) those people who would commit sin and seek forgiveness from Allah, and He would have forgiven them”.