Shaykh Albani (rahimahullallh) said, “…I say: if a person [upon the Sunnah] seeks the side of truth and accuracy and then errs it is not permissible to say that he is not from Ahlu Sunnah Wal Jamaah merely on account of him falling into an error. Or to say…that he has fallen into an innovation.
As the students of knowledge know, not to mention the people of knowledge, many scholars fall into the haram (i.e. errors and mistakes) however do they intend the haram?
How far are they from intending that. Are they sinful for that? The answer is no.
Thus, there is no difference between a scholar who falls into istihlal (making halaal) what Allah has prohibited based on ijtihad (scholarly deduction after looking into the shariah evidences on a matter which was unclear to the scholar), which he is rewarded for, or between a scholar who falls into an error which he does not intend and has rather intended the Sunnah and erred. There is no difference between either this one or that one. For this reason, we complain about this commotion which is taken place today…between Ahlu Sunnah themselves.
For it has emerged among them that one thinks a person has opposed Ahlu Sunnah in some issues and then he makes tabdee (declares the person to be a innovator) of him and expels him from Ahlu Sunnah. It is enough for them to say that the person has erred firstly, and then it is upon them to establish the proof from the Book, Sunnah and what the Salaf traversed [to prove that this person is an innovator as they claim].
Secondly as for increasing division and differing [every time a person from Ahlu Sunnah falls into an error] then this is not from the custom of Ahlu Sunnah at all! For this reason, it is not permitted to banish one who errs in an issue…whether based on a foundational issue [of aqeedah/manhaj] or a subsidiary issue [of fiqh]…It is not permitted to regard him as misguided [immediately and automatically] rather he is dealt with in a way which is better, [so he is advised with evidences from the Quran, authentic Sunnah and speech of the Salaf in private with gentleness and kindness repeatedly and his error is publicly warned against if it was done/said in public. All of that has to be done before he is even considered misguided and an innovator. Before that he is deemed to be a person upon the Sunnah who has erred mistakenly in an issue].”
Ref: Silsilah Huda wa Nur, no.734
Posted by Abdul Kareem Ibn Ozzie