quote:

"...a man who deliberately opposes the truth and acts contrary to the Pious ones who came before him, he is astray, leading others astray, a rebellious devil within the Ummah. It is a duty upon those who know of him to warn the people against him and to explain his condition to them so that no one falls into his innovation and is destroyed."

Indeed, it is compulsory upon everyone who is aware of the truth to support it. Any innovator who knows the truth, and it has been made clear to them that this (act/belief) is a misguided innovation, but refuses to abstain from it and instead adheres to and defends it is astray, leading others astray, a rebellious devil within the Ummah. It is necessary to inform the people of his real condition and warn them against him otherwise he will mislead some of the students of knowledge, deceive them and call them to his innovation. Nothing should hinder someone who understands his state from clarifying it to the people and warning against him - it is upon them to do this to fulfill their duty - so that those who do not recognise his innovation may forsake him. Whoever claims that criticising the people of innovation leads to disunity and separation is misguided because he desires that the Ummah unite upon misguidance. Islaam does not tolerate this kind of (attitude); Islaam does not accept this (behaviour). Abstaining from clarifying (the truth) is a rejection of a (form) of Jihaad that Allaah has commanded with in His Saying:  At-Tawbah (9):73 يَا أَيُّهَا النَّبِيُّ جَاهِدِ الْكُفَّارَ وَالْمُنَافِقِينَ وَاغْلُظْ عَلَيْهِمْ وَمَأْوَاهُمْ جَهَنَّمُ وَبِئْسَ الْمَصِيرُ O Prophet (Muhammad (sallallaahu alayhi wasallam))! Strive hard against the disbelievers and the hypocrites, and be harsh against them, their abode is Hell, - and worst indeed is that destination. Also, the Prophet (Sallallaahu 'alayhi wa sallam) said in a hadeeth: "The reverence of people should never stop any of you from speaking the truth if you hear or see it."(This hadeeth is) reported by Ahmed in his Musnad, 50, 53 and 84, with an authentic chain of narration. Success is granted by Allaah.[1]