Who on Earth is Faultless?

Allah the Almighty makes clear that people who make mistake, but then return to Him in sincerity and ask for forgiveness, will be forgiven. As long as believers are sincerely sorry for what they have done, they must never lose hope in Allah's mercy regardless of the sin's magnitude. This truth is emphasized in the following verse:

"My servants, you who have transgressed against yourselves, do not despair of Allah's mercy. Truly Allah forgives all wrong actions. He is the Ever-Forgiving, the Most Merciful. (Az-Zumar 39:53)

Our Prophet also stated that Allah the Almighty accepts the believers' repentance:
"If you are innocent, Allah will soon reveal your innocence. If you have committed a sin, repent to Allah and ask Him to forgive you, for when a person confesses his sin and asks Allah for forgiveness, Allah accepts his repentance." (Al-Bukhari)

This is one of Islam's greatest favors and leniencies. Falling into despair after making a mistake, as well as thinking that one will be unable to get back on one's feet when the religion has made such an allowance, is just gross conjecture. Those who ignore Allah's allowance oppress their souls and, at the same time, fail to apply one of Islam's requirements.

The Qur'an's leniency prevents many of those acts that violate it in many ignorant societies. For example, ridiculing and degrading people who make mistakes in ignorant societies can never flourish where Qur'anic manners predominate. On the contrary, where such manners abide, those people who have returned to Allah and asked His forgiveness as sincere believers will live their lives in peace, happiness, and eagerness.
It is incompatible with the Qur'an for one to fall into despair after having sinned, knowingly or unknowingly.

A person's superiority can be measured only by piety, that is, the degree to which they commit themselves to Almighty Allah and the Qur'an. Whereas in ignorant societies the people's faults and mistakes are of the utmost importance, in societies where the Qur'anic ideals prevail, a person's past mistakes and sins are never mentioned. The important thing is to receive Allah's forgiveness. To condemn and censure somebody whom Allah has promised to forgive cannot be valid or legitimate under any circumstances.

To think of oneself as being faultless, sinless, and perfect is no different than claiming divinity, for humanity is prone to making mistakes and committing sins. As human beings are weak creatures, Allah has made it known that He is most forgiving and accepting of repentance. This is why it would be incompatible with the Qur'an for someone to fall into despair after having listened to his or her ego and sinned, either knowingly or unknowingly. After making a mistake, believers learn their lessons, see the truth after regretting their actions, immediately seek refuge in Allah, and do their best not to make that same mistake again.

Undoubtedly, believers take the utmost care in avoiding mistakes and sins, and in observing the limits set by Allah. But despite this fact, believers still may make a mistake or sin. But after doing so, believers characteristically return to Allah and seek forgiveness. As a result, Allah's Names, such as The Acceptor of Repentance (at-Tawwab), The All-Forgiving (al-Ghafur), and The Beneficent (ar-Rahman), become manifest upon those believers who regret their mistakes and turn to Allah.
Muslims who sin but repent and seek Allah's forgiveness should not grieve.

Just as believers make mistakes and repent, so do they reflect upon their mistakes with the concept of destiny in mind. First of all, such mistakes have been written into their destiny in order to allow them to grow in this world and enable them to move closer to Allah. Once they ask for forgiveness, these mistakes become a way for them to receive rewards, for after vowing to abandon that particular mistake and displaying Qur'anic values by repenting immediately, mistakes actually raise the sincere believers' degree in the afterlife. They cause believers to mature and become more aware of their deficiencies, weaknesses, and servitude, for the important thing is to abandon the sin, repent immediately, and truly regret what one has done.

In other words, believers who sin but then repent and seek Allah's forgiveness should not be seized by grief and hopelessness, for hopelessness displeases Allah the Almighty. After making a mistake, the enthusiasm, fervor, and joy of believers should not diminish. On the contrary, they increase.