Answered by Shaykh Yūsuf Badāt
Is it permissible for Muslims to attend non-muslim funerals?
Jazākumullāhu Khayran/ Thank you for your question.
In principle, there is no objection in attending non-Muslim functions or funerals. However, the caution a Muslim must take, is that one should not participate in anything, at the function, which is Islamically prohibited such as worship to other than the Almighty and or consuming non-ḥalāl items.
If it is a funeral of a close friend or relative, one should attend and pay respects. However, while doing so, one is not to actively engage in any action that is prohibited in Islam. One is not to glorify anything unislamic at the event. A believer must always adhere to Islamic values and principles.
If at any function, one feels they will be negatively influenced by unislamic activities, evil or harm, one should abstain.
The Prophet Muḥammad (peace and blessings upon him) instructed ‘Alī (may Allāh be pleased with him) to fulfil the final rites of burial for his non Muslim father, Abū Ṭālib. (See: Abū Dāwūd)
And Allāh Knows Best.