What should we do when there is a difference of opinion among the schools of thought or the imams on a certain matter? Is it permissible to follow any of them, or is a specific school of thought preferable? On what basis can one choose if there is a choice?

The imams of the four madhhabs are imams of guidance, and their differences stem from their preferred evidence. People are of two types: one type is capable of knowing the evidence, and thus must follow it; the other type is not qualified to know the evidence, and thus may follow a specific madhhab. It is not obligatory for a Muslim to imitate a specific scholar in everything he says, nor to commit to the madhhab of a specific person other than the Messenger of Allah, peace and blessings be upon him. Rather, a person follows the madhhab of a specific person due to his inability to know the Sacred Law through any other means.