What is the ruling on praying in a mosque built with usury in non-Muslim countries? Is it permissible to refrain from praying therein and instead pray in another mosque built with donations? Is it permissible to eat from the food of the banquets held by this mosque?

Allah Almighty has forbidden usury, and it is absolutely impermissible to take a usurious loan, even if it is for purchasing a place to be used as a mosque, because Allah is good and accepts only what is good. The ruling on usury in the land of disbelief is the same as its ruling in the land of Islam. Prayer is permissible in a mosque built with a usurious loan, and gathering in it is also permissible, because once the loan is received, it enters into the possession of the borrower and becomes a debt upon him, even though the borrower is sinful for dealing with usury. If the builders repent, then prayer in both mosques is equal. But if they persist, then prayer in the other mosque is better, to deter those who might follow their example.