Is it permissible to offer the funeral prayer for those who call themselves Muslims but commit polytheistic acts and do not know the declaration of Tawhid, even though they may not be hostile towards Islam and may demonstrate some actions such as offering sacrifices, giving charity, or donating to the mosque?

Whoever abandons prayer, denying its obligatory nature, while knowing about it, has committed a major act of disbelief (kufr akbar). It is not permissible to offer the funeral prayer (salat al-janazah) for him, nor is he to be treated as a Muslim. As for whoever abandons it out of laziness, scholars have differed regarding his excommunication (takfir). According to the view that he has committed disbelief, it is not permissible to offer the funeral prayer for him nor to bury him in Muslim cemeteries. The hypocrites during the time of the Prophet, peace be upon him, outwardly performed prayers. As for those who are ignorant of the rulings, or interpret them differently, or only know the Shahadah and abandon prayer due to the absence of someone to teach them, they are to be treated as Muslims, and the funeral prayer is to be offered for them. It is imperative to teach people their religion if ignorance becomes widespread.