Q2 : Can evil be changed with one's hand (by taking action)? Who should change evil with his hand? Please, support the answer with evidence. May Allah preserve you!
A : Allah (Glorified and Exalted be He) described the believers of denouncing evil and enjoining what is good. He (Exalted be He) says:
The believers, men and women, are Auliyâ' (helpers, supporters, friends, protectors) of one another; they enjoin (on the people) AlMa'rûf (i.e. Islâmic Monotheism and all that Islâm orders one to do), and forbid (people) from A lMunkar (i.e. polytheism and disbelief of all kinds, and all that Islâm has forbidden)
Allah (Exalted be He) also says: Let there arise out of you a group of people inviting to all that is good (Islâm), enjoining AlMa'rûf (i.e. Islâmic Monotheism and all that Islâm orders one to do) and forbidding AlMunkar (polytheism and disbelief and all that Islâm has forbidden).
Allah (Exalted be He) also says: You [true believers in Islâmic Monotheism, and real followers of Prophet Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) and his Sunnah] are the best of peoples ever raised up for mankind; you enjoin AlMa'rûf (i.e. Islâmic Monotheism and all that Islâm has ordained) and forbid AlMunkar (polytheism, disbelief and all that Islâm has forbidden)
There are many verses that affirm the duty of enjoining what is good and forbidding what is evil. That is because of the importance of this issue and the great need for it.
According to an authentic Hadith, the Prophet (peace be upon him) says: "Whoever, among you, sees something abominable should rectify it with his hand; and if he has not strength enough to do it, then he should speak against it; 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." Narrated by Muslim in his Sahih.
Changing evil by one's hand should be done by those who are able to do that such as rulers and the competent authority and bodies in charge of such matters in the areas over which they have been appointed, the emir within his scope, the judge within his jurisdictions, and a man in his own house with his children and household according to his ability.
But if he is not able to do that, or if changing it with his hand may lead to division and conflict or result in worse harm, then he should not change it with hand. Rather, he should change it with his tongue by speaking against it. That will be sufficient lest changing it with hand should lead to a worse evil than that which he is seeking to change as stated by the scholars.
In the case of changing evil with his tongue, it is sufficient for him to say, "O my brother, fear Allah, this is not permitted! You should stop this! You should do such and such, etc." in a proper manner. After speaking against it, finally comes the role of the heart i.e. to hate the evil in one's heart, show this dislike openly, and avoid sitting with those who do it. Allah is the Source of strength.