“And do not eat that on which Allah’s name has not been mentioned.” (Surah Al An’am 6:121)
Whether or not animals slaughtered by present day Jews and Christians are Halal (permissable) or Haram (impermissible) is an issue that is differed about. The safer Fatwa (verdict) is that it is Haram if unnecessary. (Majma’-ul-Anhur)
The Jews and Christians of our time explicitly express their belief that Sayyiduna Isa and Sayyiduna Uzair (as) were sons of God (Allah (ta) forbid). It is clearly established that there is no dire need to consume meat slaughtered by them. Thus it is necessary to excercise caution (Al Ihtiyat) because there is a difference of opinion between the Scholars in relation to the permissibility of the meat of animals which sacrificed by the present day Jews and Christians. Holding onto the position that it is impermissble is more preffered when there is no necessity (Dharurah). This is what is stated in Majma’ul-Anhur.