He—may Allah Most High have mercy on him—was asked:
“Is someone sinful for believing that those who are not prophets can attain the rank of the prophets, to the point that they feel secure from Allah’s devising?”
He replied:
Whoever believes that among the friends of Allah there are those who are not obliged to follow and obey the messengers is an unbeliever. He must be called upon to repent; if he repents, so be it; otherwise, he is to be put to death. This includes someone who believes that among the community of Muhammad, may Allah bless him and grant him peace, there are those who have no need to follow him, just as al-Khidr had no need to follow Moses. Moses’s mission was not universal, unlike that of Muhammad, may Allah bless him and grant him peace, who was sent to everyone. Everyone is therefore obliged to follow his commands. If someone who believes that he is exempt from obeying him is an unbeliever, then what of someone who believes that he is superior to him, or that he can become his equal?
As for someone who believes that certain friends of Allah know that they are among the people of Paradise—just as a number of the Companions were given glad tidings of Paradise, and just as Allah may make known to some of His friends that they are among its people—he is not an unbeliever on that account. Even so, he must still fear Allah Most High. And Allah knows best.