Answered by Shaykh Abdurrahman ibn Yusuf Mangera
If there is a prayer in jamat, is it okay for me to join this even though the aqida of the imam leading the prayer is different, or if you don’t know the beliefs of the imam?
Assalamu alaykum
In the name of Allah the inspirer of truth.
The Prophet Sallallahu alayhi wasallam said, “Pray behind every obedient and transgressing person” (Bayhaqi from Abu Hurayra radhiyallahu anhu).
This means the prayer behind such a person is permissible and scholars have stated that it will not have to be repeated either.
However, praying behind someone who holds deviant beliefs, i.e. he is an innovator in beliefs, or he commits major sins and transgresses openly, should be avoided where reasonably possible. It is prohibitively disliked [makruh tahrimi] to choose to pray behind such people and for the community to make such people their imam. However, if there are no other congregations taking place close by or avoiding this one will create fitna then one should pray behind such person [and will not have to repeat his prayer afterwards either], and it will not be considered prohibitively disliked.
In fact, ‘Allama Haskafi has related in his al-Durr al-Mukhtar that it would be superior to pray behind an innovator in beliefs or a open transgressor than praying alone, although the same reward will not be gained as praying behind a pious knowledgeable scholar (al-Durr al-Mukhtar1:376-377).
If the beliefs of a person, however, take him out of the fold of Islam then prayer behind such a person is not permissible. The prayer would have to be repeated if performed behind such a person. However, one must consult reliable scholars before making judgments on their own concerning the beliefs of such people, as this is a very delicate task.
[The above has been concluded from al-Durr al-Mukhtar1:376-377 and Ahsan al-Fatawa of the late Mufti Rashid Ludhyanwi 3:262-263]
In the case of not knowing the beliefs of someone, one is not obliged to investigate and harbor undue suspicions. We are told by Allah to avoid suspicions, hence, they should be avoided as far as possible unless there are strong reasons to act otherwise.
And Allah knows best.
Wassalam
Abdurrahman ibn Yusuf