The ’Allaamah, the Shaykh, Saalih Ibn Fawzaan al-Fawzaan may Allaah preserve him was asked the following question:
“Is not refuting the people of innovation and concealing their falsehood and defending them from deceiving the Muslims?”
Shaykh Saalih al-Fawzaan replied,
“This is from major deception of the Muslims, being silent about the people of innovation (bid’ah) and not clarifying their bid’ah, this is from deceiving the Muslims and if in addition to that he praised them (the innovators) than this is worse and more evil… and refuge is sought with Allaah.
So what is obligatory upon those who have knowledge is to make clear the innovations and newly invented matters (in the religion) and to prohibit them and warn against these innovations and to not be silent because indeed silence is from concealing (knowledge) (Allaah says:)
“Verily, those who conceal the clear proofs, evidences and guidance, which We have sent down, after We have made it clear for the people in the Book, they are the ones cursed by Allaah and cursed by the cursers. Except those who repent and do righteous deeds, and openly declare (the truth which they concealed). These are the ones who I will accept their repentance. And I am the One Who accepts repentance, and the Most Merciful.” [Sooratul-Baqarah 2:159-160]
It is not permissible for the Muslim that has knowledge to be silent about bid’ah and oppositions (in the religion) and he is to make them clear to the people because if he was silent, the people will use (his silence) as proof, and they will say if this was unlawful or prohibited, the scholar so and so would of not been silent about it and he sees it (innovation, opposition).
[Q]: We are youth of Ahlus-Sunnah from the city of Baytul-Faqeeh. We do not have a musallaa (place of Prayer) for ourselves in which we may pray the ’Eed Prayer. However, there is a common musallaa within the city and the khateeb (speaker) is a Soofee and there are others there who are Surooriyyeen. Due to that, we travel to a neighbouring town that is five kilometers away from us. Due to this, we find criticisms from some of our brothers who say, ‘This is considered splitting up the unity of the Muslims. So what is your instruction concerning that? May Allaah preserve you.
[A]: That which we advise with is at-Tamayyuz (being distinct and clearly distinguished). So how can you pray behind a Soofee who propagates his Soofiyyah?!! And the Messenger (sallallaahu ’alayhi wa sallam) said, “Whosoever from amongst you sees an evil, then let him change it with his hand. So if he is unable to do that, then let him speak out against it with his tongue. So if he is unable to do that, then let him hate it within his heart. And that is the weakest of eemaan (faith).” 
And safety from fitan (trials, tribulations) comes through keeping a distance from the innovators and remaining near beneficial knowledge and calling to Allaah. This is what is required. May Allaah bless you.
As for those who discourage you from this, then they are either infiltrators amongst Ahlus-Sunnah from the Ikhwaanul-Muslimoon, or they are from Ahlus-Sunnah, but they are not familiar with the plots of the hizbiyyeen (biased partisans).
So we advise all of Ahlus-Sunnah to make themselves clearly distinguished and distinct (tamayyuz) with regards to the ’Eed Prayers, the Jumu’ah Prayers and the rest of the Prayers that take place within the mosque and outside of it. At-Tamayyuz is absolutely necessary. After that, the people will come if Allaah so wills, as long as you select a khateeb (speaker) who has benefited in knowledge to the extent that he can benefit the people and he has wisdom. The people will come, with the permission of Allaah, and pray with you and abandon that Soofee.
So I raise a complaint to Allaah with regards to these brothers of ours from Ahlus-Sunnah. He may be a Sunnee, one who loves goodness, but he says the likes of this!! Leave alone those who say this. Allaah says,
“Had they gone forth with you, they would not have increased you except in confusion, and they would have been active amongst you.” [Sooratut-Tawbah 9:47]
So we keep a distance from the innovators and from those who have diseased hearts. And we establish the Sunnah of the Messenger of Allaah (sallallaahu ’alayhi wa sallam). And Allaah the Glorified and Exalted says in His Noble Book,
“And keep yourself patient by being with those who call upon their Lord in the morning and the evening, seeking His countenance. And let not your eyes pass beyond them, desiring adornments of the worldly life, and do not obey one whose heart We have made heedless of Our remembrance and who follows his desire and whose affair is ever in neglect.” [Sooratul-Kahf 18:28]
So we are not concerned in the least with the speech of the innovators. They will not be pleased up until you become innovators like them. So from the beginning of the affair, we have isolated ourselves from the innovators and we continue to isolate ourselves from the innovation. And Allaah is One from Whom aid is sought. 
: Related by Muslim (no. 49), Aboo Daawood (no. 1140), Ibn Maajah (no. 4013) and an-Nisaa‘ee (8/111).
: Refer to the audio cassette: As‘ilah min Baytil-Faqeeh of Muqbil Ibn Haadee.