It is narrated on the authority of Sayyiduna Abu Sa’eed (radi Allahu anhu) that Sayyiduna Rasoolullah (sallal laahu alaihi wasallam) said: “He who amongst you sees something abominable should modify it with the help of his hand; and if he has not strength enough to do it, then he should do it with his tongue; and if he has not strength enough to do it (even) then he should (abhor it) from his heart, and that is the least of faith.” (Muslim)
This Hadith throws a good deal of light on how the society is to be kept safe and secure from evil and corruption. It has been made an obligatory act for every Muslim to see carefully that the moral health of the community does not deteriorate, and whenever there is any sign of decadence in any quarter it should be checked with determination. Islam does not allow its followers to lead the life a silent spectator in the world; it has made them duty-bound to eradicate evil, since once it is allowed to creep into the society, it corrodes it and the whole social structure crumbles down. It has, therefore, been enjoined upon the believers to take effective measures to fight against it. Those who have power enough to check it with force must do so, while others by means of preaching and persuasion should try to sweep it out of effective existence, but if the circumstances become so adverse that even this becomes impossible, then we should at least keep our conscience alive to the fact that it is an evil and should be strongly abhorred, and wait for a suitable opportunity to drive it out completely.
It must be made clear in this connection that the commentators of the Hadith are of the view that forbidding with the help of hand implies the power of the State. That it is the duty of the State and society to check the evil in all its forms and shapes and in case of necessity even the strictest measures may be adopted.
Imam Nawawi (alaihir rahmah) says there is a consensus of opinion that this act of bidding the people to do good and forbidding them to do wrong is obligatory on believers.