Enjoining Good and Forbidding Evil
An important aspect of Jihad, striving and struggling, is to fight against oppression and injustice in all its forms. One form of this Jihad is to encourage and enjoin the good and forbid the evil. There are ample evidences for this from both the Quran and the Sunnah:
“The believers, men and women, are Awliyaa’ (helpers, supporters, friends, protectors) of one another; they enjoin (on the people) Al‑Ma‘roof (i.e. Islamic Monotheism and all that Islam orders one to do), and forbid (people) from Al‑Munkar (i.e. polytheism and disbelief of all kinds, and all that Islam has forbidden)”[Quran: Surah al Tawbah 9: Ayah 71]
“Let there arise out of you a group of people inviting to all that is good (Islam), enjoining Al-Ma‘roof (i.e. Islamic Monotheism and all that Islam orders one to do) and forbidding Al-Munkar (polytheism and disbelief and all that Islam has forbidden)” [Quran: Surah Aal ‘Imraan 3: Ayah 104]
“You (true believers in Islamic Monotheism, and real followers of Prophet Muhammad 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)” [Quran: Surah Aal ‘Imraan 3: Ayah 110].
And Allah also says:
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression” [Quran: Surah al-Maa’idah 5: Ayah 2].
There are many verses which speak of enjoining what is good and forbidding what is evil; that is because of the importance of this issue and the great need that exists for it.
It is narrated by Anas (رضي الله عنه) that Allah's Apostle (صلى الله عليه و سلم) said, "Help your brother, whether he is an oppressor or he is an oppressed one. People asked, "O Allah's Apostle (صلى الله عليه و سلم)! It is all right to help him if he is oppressed, but how should we help him if he is an oppressor?" the Prophet (صلى الله عليه و سلم) said, "By preventing him from oppressing others." [Saheeh Bukhari]
According to a saheeh hadeeth, the Prophet (صلى الله عليه و سلم) said: “Whoever among you sees an evil action, let him change it with his hand [by taking action]; if he cannot, then with his tongue [by speaking out]; and if he cannot, then with his heart [by at least hating it and believing that it is wrong], and that is the weakest of faith.” [Saheeh Muslim].
Changing evil by one's hand should be done by those who are able to do that, such as those in positions of authority and the bodies in charge of such matters. In its simplest form it means that when you see an injustice or oppression, such as a person being attached, and you have the ability to intercede and stop that injustice, you do so.
But if the person is not able to do that, i.e. to stop the injustice with ones hand, or if changing it with his hand will lead to fitnah (tribulation) and conflict, and cause more harm than good, then he should not change it with his hand, rather he should change it with his tongue, by speaking out. That will be sufficient lest changing it with his hand will lead to a worse evil that that which he is seeking to change.
In the case of changing evil with his tongue, it is sufficient for him to say, “O my brother, fear God, what you are doing is wrong, you should stop this, you should do such and such” and other good words spoken in a proper manner.
After the tongue comes the heart, i.e., hating the evil in one's heart, showing that one hates it, and not sitting with those who do it. All of these come under the heading of changing it with one's heart.
Based upon the fatwas of Shaykh ‘Abd al-‘Azeez ibn Baaz, Majallat al-Buhooth al-Islamiyyah, 36/121-122