Judging Others

As Muslims, the default assumption we should have about other people in any matter is that they are free of blame. Islam demands fairness and impartiality when it comes to judging others.

Allah says:
"And when you speak, then be just, though it be (against) a relative."
[Noble Quran 6:152]

He also says:
"O you who believe! Stand out firmly for Allah, as witnesses to fair dealing, and let not the hatred of any people make you swerve to wrong and depart from justice. Be just: that is next to piety: and fear Allah. For Allah is well-acquainted with all that you do." [Noble Quran 5:8]

It is wrong for a person to accuse anyone else of something wrong except with full knowledge and tangible proof.

It is forbidden to base a judgment against someone on hearsay, conjecture or suspicion.
Allah says:
"O you who believe! If a wicked person comes to you with any news, ascertain the truth, lest you harm people unwittingly, and afterwards become full of repentance for what you have done." [Noble Quran 49:5]

He also warns us:
"O you who believe! Shun much suspicion; for lo! Some suspicion is a sin."
[Noble Quran 49:12]

In those cases where one is compelled to mention another persons faults, it is best to mention that persons good points as well. It is wrong to exaggerate the importance of the persons error or stress the fault too much, especially if it is possible that the error was an honest mistake or in a matter where the truth is not 100% clear.

If a persons error is clearly manifest and established by solid evidence, then it is not wrong to warn people against the error and clarify the truth. However, that correction must be carried out appropriately, in a gentle manner that does not drive people away. The mistake itself should be corrected without delving into anything beyond that. For example, the person who made the mistake should not be accused of having bad intentions or an evil motive.

Adth-Dthahabi, speaking about the mistakes of the scholars, said the following: [Siyar al-Alam al-Nubala' (14/374)]:

If we were to discredit every person who made mistake in judgment or declare those people as innovators - people who are essentially of good faith and sincerely seek the truth - then scarcely would any of our scholars be spared.