Shaykh Ali al-Hadaadi (may Allah preserve him):
May Allah be good to you. This question has been repeatedly asked many times in various different ways and the summary of this question is; how do we differentiate between the callers to Sunnah and the callers to bid’ah?
Shaykh Saalih al-Fawzaan (may Allah preserve him):
We differentiate between them by the different types of things they call to. So if they are calling to the Sunnah and the Aqeedah of the Pious Predecessors, and likewise the Aqeedah of Ahlus-Sunnah wa al-Jamaa’ah whilst traversing upon the correct methodology, then they truthful in their call.
However if they ascribe themselves to calling to Allah (by Da’wah), and they spread ideologies that are in opposition to calling to Allah, then they are the callers to misguidance and it’s Waajib (obligatory) to warn against them!
Translated by Markaz DaarutTawheed