In his well known book “The Lawful and the Prohibited in Islam”, the renowned Muslim scholar, Sheikh Yusuf Al-Qaradawi, states: “While Islam takes an uncompromising attitude toward polytheists, it is lenient toward the People of the Book, for they are closer to Muslims in their belief in divine revelation, Prophethood, and other fundamentals.
Thereby, according to Islam, the food prepared by the People of the Book is permissible for Muslims to eat. Allah Almighty says, “Today whatever is good is made lawful to you. And the food of those who were given the Scripture (before you) is permitted to you and your food is permitted to them…” (Al-Ma’dah: 5)
The application of the phrase, “the food of those who were given the Scripture” is general and includes their meats, produce, and other foods. All of these are halal for us save what is haram in itself such as the flesh of a dead animal, pork, and flowing blood, as these are haram regardless of whether they are obtained from a Christian, a Jew or a Muslim.
Another important rule worth mentioning in this respect is the one stating that: “What We Do Not See Should Not Be Probed Into”
This juristic rule means that it is not required of a Muslim to inquire about non-resolvable matters, such as posing the questions about how a certain animal is slaughtered: Are all the Islamic conditions of slaughtering animal met? Was the name of Allah mentioned while slaughtering it or not?
So, based on this fact, an animal slaughtered by a Muslim, regardless of his being ignorant or sinful, or by someone from among the People of the Book, is halal for Muslims.
It is reported that one of the Companions, may Allah be pleased with them all, addressed the Prophet, peace and blessings be upon him saying: “People bring us meat, and we do not know whether Allah’s Name was mentioned during the slaughtering or not.. Is it Halal to eat such meat?” The Prophet, peace and blessings be upon him, replied, “Mention the Name of Allah (over it) and eat (it).”
Concerning the application of this Hadith, scholars say: This gives full support to the juristic rule stating that all people’s actions and practices are basically deemed correct and valid until the contrary is proven.”