Praise be to Allah.
Enjoining what is good and forbidding what is evil is one of the most important commands of Islam, and it is the one of the most important features of the ummah (nation) that possesses much goodness, as Allaah says (interpretation of the meaning):
“You (true believers in Islamic Monotheism, and real followers of Prophet Muhammad صلى الله عليه وسلم and his Sunnah) are the best of peoples ever raised up for mankind; you enjoin Al-Ma‘roof (i.e. Islamic Monotheism and all that Islam has ordained) and forbid Al‑Munkar (polytheism, disbelief and all that Islam has forbidden)”
[Aal ‘Imraan 3:110]
This involves conditions and etiquettes that have been explained in the answer to question no. 96662.
If denouncing it will lead to a greater evil, then it is not obligatory; rather it is haraam in that case, because Islam came to achieve what is in people’s best interests and to ward off and reduce that which is evil and harmful.
If a young man were to occupy his time in denouncing every adorned woman who crossed his path – in a land where there is a great deal of tabarruj – that may cause him to be tempted and may lead to others thinking badly of him, as well as taking up a lot of his time. Rather he should focus on calling his female relatives and his family, and explaining to them that tabarruj is haraam, and that hijab is obligatory. There is much good in that, and it will reduce the evil.
A number of scholars have stated that if it seems most likely that there will be no response and the person addressed will not benefit, then denouncing it is not obligatory.
Ibn Rushd (may Allaah have mercy on him) said in al-Bayaan wa’l-Tahseel: Enjoining what is good and forbidding what is evil is obligatory for every Muslim, subject to three conditions:
1-That he should know what is right and what is wrong. There is no guarantee that he will not forbid something that is right and enjoin something that is wrong if he is ignorant of the ruling.
2-The denunciation of evil should not lead to a greater evil, such as if he tells people not to drink alcohol and that may result in murder and the like.
3-He should know or think it most likely that his denunciation of evil will put a stop to it, and that his enjoining good will be effective and beneficial.
The first two conditions are essential for it to be permissible, and the third condition is essential for it to be obligatory. If the first and second conditions are not met, then it is not permissible to enjoin what is good and forbid what is evil. If the third condition is not met, but the first and second ones are, then it is permissible for him to enjoin what is good and forbid what is evil, but it is not obligatory. End quote from al-Madkhil by Ibn al-Haaj (1/70).
Al-Ghazaali said in al-Ihya’ (2/328): If he knows that his denunciation will be to no avail, but he does not fear any harm, then he does not have to enjoin what is good or forbid evil because it will be to no avail, but it is mustahabb, so as to manifest one of the symbols of Islam and to remind the people of their religion. End quote.
See: al-Furooq by al-Qaraafi (4/255).
From this it may be noted that if it is thought most likely that there will be no response, it is no longer obligatory.
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) said:
Enjoining what is good and forbidding what is evil is a communal obligation (fard kifaayah); if sufficient people undertake it, it is waived for the rest, but if not enough people undertake it, then all the people are obliged to enjoin what is good and forbid what is evil. But it is essential that it be done with wisdom, kindness and gentleness, because Allaah sent Moosa and Haroon to Pharaoh and said (interpretation of the meaning):
“And speak to him mildly, perhaps he may accept admonition or fear (Allaah)”
As for violence, whether in word or deed, this is contrary to wisdom and is contrary to what Allaah has enjoined.
But sometimes a person may be faced with something and say “This is a well known evil,” such as shaving the beard for example, which everyone knows is haraam – especially those who live in this land (Saudi Arabia) – and he says: if I were to stop every time I see someone with a bare face – and how many of them there are – and tell him not to do this, then I would miss out on a lot of good. In this case, perhaps we should say that the duty of denouncing is waived, because that would cause him to miss out on a lot of good. But if you happen to meet this man in a shop, restaurant or café, in that case it would be good to remind him to fear Allaah and say: This is something haraam, and if you persist in a minor sin then in your case it will become a major sin – and say something appropriate.
Liqaa’aat al-Baab il-Maftooh (110/ question no. 5)
And Allaah knows best.