What is the fate of the sins and transgressions committed by a repentant servant after he has pledged to Allah to repent, and who bears their consequences if Allah forgives him?

Allah Almighty created mankind for His worship alone, and He sent messengers as bearers of good tidings and as warners, so that people would have no excuse after the messengers. And whoever submits [to Allah] has chosen happiness. Because humans are prone to error and forgetfulness, Allah prescribed repentance and opened its door until the Day of Judgment.

Sins are of two types: 1. Against Allah Almighty: Such as neglecting obligations or committing prohibitions. If the perpetrator is punished with a [prescribed] Hadd penalty in this world, it serves as an expiation for him. If no Hadd penalty is imposed on him and he repents, Allah accepts his repentance. As for one who meets Allah with these sins without repentance or a Hadd penalty, he is under Allah's will on the Day of Judgment, except for Shirk (associating partners with Allah), which is not forgiven. 2. Against a created being: Such as aggression against property, honor, or bodies. Repentance from such sins requires restoring rights to their owners or seeking their forgiveness. Whoever fails to do so will remain burdened by the consequence of his sin on the Day of Judgment, and an amount equal to his injustice will be taken from his good deeds.

There is no evidence that a sinner must necessarily be punished in this world. Whoever is punished, it is an expiation for him, and whoever repents, Allah accepts his repentance. The claim that the punishment for a sin is borne by someone other than the sinner is false, for Allah does not hold anyone accountable for another's sin, as Allah Almighty says: ﴿And no bearer of burdens will bear the burden of another.﴾ Whoever has lived a life full of disobedience must return to Allah with repentance and seeking forgiveness, for Allah forgives all sins.