Attending a Sikh wedding in a Sikh temple
28-4-2014 | IslamWeb
Question:
Asalaamu Alykum, A sikh friend of mine invited me to his wedding, its going to be at their temple. He mentioned that I have to cover my head if I'm going to enter their temple as a sign of respect to their holy book. My question is, if I do this will it be an act of Shirk?
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
Such temples, especially in a ceremony like this, almost always involve forbidden matters, and it is not permissible for a Muslim to be present in a place where there are violations of religion unless for a valid purpose such as forbidding evil. Allaah says (what means): {And when you see those who engage in [offensive] discourse concerning Our verses, then turn away from them until they enter into another conversation. And if Satan should cause you to forget, then do not remain after the reminder with the wrongdoing people.}[Quran 6:68]
Jaabir 
narrated that the Prophet said: “Whoever believes in Allaah and the Last Day, he should not sit at a table where wine is being served.” [At-Tirmithi]
Accordingly, you are not permitted to participate with these non-Muslims in this ritual, which is covering the head, or in any rituals of their religion, as this is a sin that could lead the doer to disbelief. The book entitled Al-Mufassal, when interpreting the Hadeeth 'Whoever changes his (Islamic) religion, kill him’, reads: “The words of the Prophet : ‘Whoever imitates a people is one of them’ could be interpreted that he would be a disbeliever like them if he imitates them in what is disbelief such as venerating the day of their festival as a glorification for their religion, or wearing the clothes peculiar to them while intending to take his religion lightly, otherwise he would be sinful (i.e. if his intention is otherwise, then he would bear sin but he would not be considered a disbeliever).”
Allaah Knows best.