This is a critical question , hence i would just quote relevant fatwa:
Whoever believes in Muhammad (peace be upon him) then associates
others in worship with Allah through making Sujud (Prostration),
vowing or slaughtering for any one other than Allah is not similar to
the People of the Book.
They are apostates who should be asked to repent for three days after
pointing out the truth to them. If they do not repent, they should be
killed.
Their properties will go to Bayt-ul-Mal (Muslim treasury) and not to
their Muslim inheritors.
It is not permissible for them to marry Muslim women and the animals
slaughtered by them are unlawful for Muslims. Moreover, their marriage
contract to Muslim women should be anulled.
The matter is different with regard to disbelievers from among the
People of the Book. They inherit from each other and their marriage is
valid. The animals they slaughter are lawful and they are to be
invited to accept Islam. If they do not accept Islam, they have to pay
Jizyah (poll tax required from non-Muslims living in an Islamic
state).
They should not be killed due to their disbelief.
May Allah grant us success! May peace and blessings be upon our
Prophet Muhammad, his family, and Companions!
Permanent Committee for Scholarly Research and Ifta'
Abdullah ibn Qaud [Member] Abdullah ibn Ghudayyan [Member]
Abdul-Razzaq Afify [Deputy Chairman ] Abdul-Aziz ibn `Abdullah ibn
Baz [Chairman]
who claim to be Muslimsthat needs specifics. Otherwise it is the same question as halal or haram. – The Truth Seaker Feb 27 at 17:29