Ash-Shaykh Muqbil, may Allah have mercy upon him, said,
“As for the funeral that contains acts of innovations, if the deceased himself is an innovator, then I advise not to attend [his funeral] and if he is not an innovator while his family and relatives or one of the innovators just took control of his funeral, then there is no harm in attending…” End translation.
He, may Allah have mercy upon him, also said,
“…If the janaazah is for a sunni while his family is from the people of innovations, we advise that the person follows the janaazah of the sunni and he should not participate with them in anything from their innovations…” End translation. [Min Fiqh al-Imaam Waadie (1/493)]
Al-Imam Muqbil, rahimahullah, said,
“…If a chaplain [i.e. a pastor] were to come [to the funeral] and utter words similar to the talqeen of the innovators (i.e. of them addressing the dead with certain words), if the person remains then inshaa Allah la bass (i.e. it’s okay) while disliking it with his heart. The proof is the hadeeth of Abu Saeed al-Khudri (may Allah be pleased with him) who said:
‘I heard the Messenger of Allah say, “Whoever of you sees an evil must then change it with his hand. If he is not able to do so, then [he must change it] with his tongue. And if he is not able to do so, then [he must hate it] with his heart. And that is the weakest [effect of] faith.”‘
And if he were to walk away, then it is better inshaa Allah” End translation. [Min Fiqh al-Imam Al-Waadie (1/498)]
A Side Note: Likewise if a person were to attend a janaazah and an innovator there begins to speak or perform certain innovations, then the person can either remain and dislike it with his heart and if he were to walk away then that is better for him inshaa Allah. And Allah knows best.
Al-Imam Muqbil rahimahullah also said,
“As for following a janaazah that is accompanied with innovations, then as long as the deceased is a Muslim it is appropriate to follow his janaazah. However if you are able to criticize, then criticize, and if you aren’t capable to criticize, then dislike it with your heart and do not participate with them in their innovations”. End translation. [Min Fiqh al-Imaam Waadie (1/492)]
AbdulFattaah Bin Uthman