Is Attending a Non-Muslim Funeral Permissible?
Question

What is the ruling of Allah concerning following the funeral procession of a non-Muslim – which has become a political practice and tradition followed by everyone?
Praise be to Allah.If there are people among the non-Muslims who can bury their own dead, then the Muslims should not bury them , or join the non-Muslims and help them to bury them, or try to please the non-Muslims by joining the funeral procession, even if this is a political practice. 
Such things are not known from the Messenger of Allah (peace and blessings of Allah be upon him) or the Rightly-Guided Caliphs.
In fact, Allah forbade His Messenger (peace and blessings of Allah be upon him) to stand by the grave of `Abdullah ibn Ubayy ibn Salul, and explained that the reason for this prohibition was that the man was a non-Muslim. Allah said (interpretation of the meaning):
“And never (O Muhammad) pray (funeral prayer) for any of them (hypocrites) who dies, nor stand at his grave . Certainly they disbelieved in Allah and His Messenger, and died while they were rebellious (and disobedient to Allah and His Messenger).” [At-Tawbah 9:84]
If there is nobody among the non-Muslims who can bury their dead, then the Muslims should bury them , as the Prophet (peace and blessings of Allah be upon him) did with those who were killed at Badr, and as he did with his uncle Abu Talib, when he died, and he (peace and blessings of Allah be upon him) said to `Ali: “Go and bury him.”
And Allah is the Source of strength. May Allah bless our Prophet Muhammad and his family and companions, and grant them peace.
For more details, please see the following answers: 14229 , 105381 , and 67576 .
And Allah knows best.