Oscar Wilde said, “Every Saint has a past and every sinner has a future.” We have many exemplaries in he Islamic tradition of those who turned to servitude and piety. Allah says in the Qur’an: ‘Believers, all of you, turn to God so that you may prosper.’ [Surah an-Nur 24:31]

Ibn Juzayy al-Kalbi (d. 741AH) comments on the above verse in his commentary Al-Tashil li ‘Ulum al-Tanzil:

“Repentance is an obligation upon every legally-responsible believer according to the evidences in the Book, the Sunnah and the consensus of the [Muslim] nation.

It has three obligations:

1. Feeling remorse over the sin due to disobeying God, not due to some harm that may have come to one’s wealth or self.
2. Refraining from the sin as immediately as possible, without procrastination or slackness.
3. Resolving not to repeat it again; but if one does, then one renews the resolve.

It has three etiquettes:

1. To acknowledge one’s sin along with feeling utterly broken.
2. To increase in entreating God and beseeching His forgiveness.
3. To increase in doing good works so as to erase past wrongs.

It has seven degrees:

1. Repentance of disbelievers from disbelief.
2. Repentance of the sincere ones from major sins.
3. Repentance of the upright ones from minor sins.
4. Repentance of the devout worshippers from slackness.
5. Repentance of wayfarers from the defects and vices of the heart.
6. Repentance of the high-minded, scrupulous ones from doubtful matters.
7. Repentance of those spiritually witnessing God from being distracted from God.

The causes of repentance are seven:

1. Fear of punishment.
2. Hope of reward.
3. Embarrassment of being held responsible.
4. Love for the Beloved.
5. The vigilance of the vigilant one who is near.
6. Glorifying the station.
7. Gratitude for numerous bounties.

One may say Astaghfirullah or Astaghfār.