Why is enjoining what is right and forbidding what is wrong considered one of the fundamentals of the Muslim faith?

Indeed, humans are prone to forgetfulness and error, and their souls command them to evil, while Satan tempts them with disobedience. Just as bodies fall ill and need a doctor, so too do souls and hearts become afflicted with the diseases of desires and doubts. The diseases of the heart are more dangerous than the diseases of the body. To treat them, Allah has obligated believers to enjoin good and forbid evil, which is the function of the prophets, and Allah has made it the reason for the superiority of this Ummah. Neglecting this ritual leads to the spread of injustice and corruption and incurring Allah's curse, as happened to the Children of Israel.

Enjoining good and forbidding evil is a fundamental principle of religion and a jihad that requires patience and enduring hardships. Those who undertake it must be adorned with noble character, wisdom, good counsel, and gentleness. The Ummah that upholds this ritual achieves happiness and victory in this world and the Hereafter. This message is unending and obligatory upon everyone, men and women, each according to their ability: with the hand, if unable, then with the tongue, if unable, then with the heart, and that is the weakest of faith.

All Muslims must undertake reform, remove evils, and offer advice to everyone. The one enjoining good should be the quickest to do it, and the one forbidding evil should be the farthest from it. Humans are in constant need of advice and guidance.