Q 5: Can we eat meat from animals slaughtered by people of unknown 'Aqidah (creed), who commit sins while knowing that they are Haram (prohibited), and those who call upon (invoke) the Jinn (creatures created from fire), without doing so intentionally?
A: If a person is not known to have committed Shirk (associating others with Allah in His Divinity or worship), the animals slaughtered by them are Halal (lawful), if they are Muslims who testify that there is no Ilah (god) but Allah and that Muhammad is the Messenger of Allah, and are not known to have committed what entails declaring them to be Kafirs (disbelievers), then their slaughtered animals are Halal. This is so, unless they are known to have committed any act that constitutes Shirk, such as calling upon (invoking) the Jinn or the dead and seeking their help, as this is a major form of Shirk.
It is not permissible to eat meat from animals slaughtered by such a person. Invoking the Jinn includes asking them to do something, grant something, or do harm to a particular person. The same applies to those who call upon the dead or the angels, and seek their help, or make vows to them. All these are forms of major Shirk. May Allah grant us safety and protection! As for sins, they do not prohibit eating from the animals slaughtered by people who commit any of them as long as they do not regard such sins as lawful; rather, the animals slaughtered by them are Halal on condition that they are slaughtered in the way prescribed by the Shari'ah (Islamic law). As for those who regard sins as lawful, they are considered to be Kafirs (disbelievers), such as deeming permissible to commit Zina (premarital sexual intercourse and/or adultery), drinking Khamr (intoxicants), Riba (usury), undutifulness to parents, false testimony, and other similar forbidden acts on which Muslims are unanimous. We ask Allah grant us safety from all that displeases Him.