What is the ruling on factionalism in mosques, whether for an Islamic or non-Islamic party, or what is the ruling on factionalism in Islam?

The meaning and ruling of partisanship have been previously explained, differentiating between what is permissible and what is forbidden. Partisanship in its true sense, free from transgression, conflict, fanaticism, and discord, is not prohibited in the mosque. However, if it leads to contention and hatred among Islamic groups, then it is forbidden due to the corrupting effects that result from it.