How can one reconcile the permissibility of eating the meat of an unknown Muslim's slaughtered animal or the slaughtered animals of countries where the majority of their people are Muslims, with the fatwa of Sheikh Muhammad ibn Ibrahim, which stipulates that the butcher must be a Muslim of sound belief? And does this mean that all slaughtered meat is unlawful until the specific slaughterer is verified?

The basic principle is that slaughtered animals in Muslim lands are permissible, and one does not inquire about the beliefs of the slaughterer, acting upon the original presumption of permissibility. However, if it becomes clear that the slaughterer holds corrupt beliefs, such as reviling Islam or showing hostility towards it, then his slaughtered animal is not permissible.

If the slaughtering in a country is carried out by disbelievers, or if it is a country of disbelievers who are neither Jews nor Christians, then the slaughtered animal should not be eaten unless it is known that the slaughterer is a Muslim, a Jew, or a Christian, and that he is not one whose slaughtered animal is forbidden.

There is no issue in requiring verification of the slaughterer's Islam if disbelief-related beliefs have spread among those who claim to be Muslim.