Question: We are from a tribe living on the northern borders (of Saudi Arabia), and we mix with tribes from Iraq . Those people are idolatrous Shiites who worship shrines and call them Al-Hasan, Al-Husayn and
Alee. When one of them stands up he says: OAlee, O Husayn. Some people from our tribe have intermarried with them and mix with them in all circumstances. We have tried to teach them but they do not listen. I do not have enough knowledge to teach them but I hate what they do, and I do not mix with them. I have heard that we cannot eat the meat of their sacrificed animals, but some people eat their meat and do not care. Could you please clarify this matter for us?
Answer: If the situation is as you have mentioned, and those people invoke `Alee, Al-Hasan and Al-Husayn, and the like, then they are committing major Shirk (associating others with Allaah in His Divinity or worship), which takes them out of Islaam… read more here.