Whoever has not thrown off his anxieties, been purified of the evils of his self and its appetites, defeated Satan, and entered under the guardianship of Allah and the security of His protection, cannot properly enjoin what is good and forbid what is evil; and since he has not attained these aforementioned qualities, whatever affair he tackles in attempting to enjoin what is good and forbid what is evil will be a proof against him, and people will not benefit from it.
أَتَأْمُرُونَ النَّاسَ بِالْبِرِّ وَتَنسَوْنَ أَنفُسَكُمْ وَأَنتُمْ تَتْلُونَ الْكِتَابَ أَفَلاَ تَعْقِلُونَ
Anyone who does that is called upon thus: Oh- traitor! Do you demand from My creation that which you have rejected for yourself and have slackened the reins [in this regard] upon yourself?
It is related that Tha'labah al-Asadi asked the Messenger of Allah about this verse:
يَا أَيُّهَا الَّذِينَ آمَنُواْ عَلَيْكُمْ أَنفُسَكُمْ لاَ يَضُرُّكُم مَّن ضَلَّ إِذَا اهْتَدَيْتُمْ
O you who believe! Take care of your souls; he who errs cannot hurt you when you are on the right way. (5:105)
The Messenger of Allah said, 'Enjoin what is good and forbid what is evil, and be forbearing in whatever afflicts you, until such time when you see meanness obeyed and passions followed, and when everyone will have conceit about their own opinion, then you should concern yourself only with yourself, and ignore the affairs of the common people.'
A person who enjoins what is good needs to be knowledgeable about what is permissible and what is forbidden; he must be free from his personal inclinations regarding what he enjoins and forbids, give good counsel to people, be merciful and compassionate to them, and call them with gentleness in a very clear manner, while recognizing their different characters so that he can put each in his proper place.
He must see the intrigues of the self and the machinations of Satan. He must be patient in whatever befalls him, and must not seek compensation from people for that which he instructs them in, nor complain about them. He should not make use of vehemence or passion. He should not become angry for his own sake. He should make his intention purely for Allah, and seek His help and desire Him. But if people oppose him and are harsh to him, he must be patient; and if they agree with him and accept his verdict, he must be thankful, entrusting his affair to Allah and looking to his own faults.