Say [from Me]: ‘My servants, you who have transgressed against yourselves, do not despair of the mercy of Allah. Truly Allah forgives all wrong actions. He is the Ever-Forgiving, the Most Merciful.’ ”(Surat az-Zumar; 53)
It surely brings relief to their hearts, for a believer who errs could feel great regret, sorrow and guilt.
Allah has made the scope for error so wide in human beings that He has promised to forgive a person’s errors without exception, if that person is sorry and repents of what he has done.
But despite of the many consolations in the Qur’an that refresh the spirit and give hope, many human beings do not admit that they make mistakes. In spite of the glad tidings announced in the Qur’an, after making a mistake they become wrapped in despair and become anxious and downhearted.
An individual who refuses to acknowledge errors he has committed out of pride and arrogance is greatly saddened by what he has done. He has trouble accepting that he is a creature prone to making mistakes and faulty decisions, and whose actions and words may be wrong.
He does not consider that perfection and freedom from error belong only to Allah. He wants to be perfect himself. But he cannot, and the fact that some of his attitudes are wrong (despite his desire that they not be), draws him into despair.
A believer experiences deep peace by accepting his imperfections and helplessness in relation to Allah and never claims to be free from error.
It should be remembered that the tendency to err and sin—even though one may be a firm believer—makes him more aware of Allah’s perfection. One can conceive of perfection only when he had experienced imperfection.
Consciousness of his own failures and weaknesses lets him better appreciate the absolute perfection of Allah. Mohammad.com