When is a person who commits one of the nullifiers of Islam declared a disbeliever, and is it a condition that the argument be established against him?

Question:
May Allah reward you, Your Eminence, father. The questioner asks: Is it obligatory to establish the argument against a person who commits one of the nullifiers of Islam before he is declared a disbeliever? And if he dies and the argument was not established against him, is it permissible to pray for his mercy?

Answer:
If it is in the apparent matters, if the apostasy is in the apparent matters, such as shirk (associating partners with Allah) with Allah the Exalted, or insulting Allah and His Messenger, or these are apparent matters in which he is not ignorant, then he is given the opportunity to repent. If he repents, well and good; otherwise, he is killed. He is declared an apostate and given the opportunity to repent; if he repents, well and good, otherwise he is killed. As for the hidden matters that require clarification, these require clarification. He is not declared an apostate until it is clarified to him, because it was hidden from him. Yes.