How should one deal with banks, and when is holding an account and earning profits from them permissible or impermissible? Is dealing with all non-Islamic banks impermissible? What is the ruling for someone who can only find an usurious bank, and is he considered sinful if he fears the loss or theft of his money?

It is forbidden to deal with usurious banks in all transactions, such as (investment, borrowing, lending), and in opening current accounts. This is because whoever deals with them will either consume usury, or feed it to others, or assist the usurer. This is permissible only in cases of extreme necessity, such as someone who fears their money will be stolen or lost, or if a transaction forces them to deposit their money in usurious banks. In such cases, it is permissible without taking interest.