“Has everyone who curses the religion or rejects the sunnah disbelieved?
Shaikh Saalih al-Fawzaan:
“There is no doubt whatsoever in this; whoever curses the religion or rejects the Sunnah then verily he has disbelieved, because he is a denier and disbeliever in the Sunnah; also he who curses Allaah’s religion, which Allaah has chosen for his slaves; then he has cursed that which Allaah has chosen for his slaves and legislated for them, so this one has cursed Allaah – jalla wa ‘ala – there is no doubt at all of his disbelief.”
Translated by our brother Abu Abdir-Razzaaq Amjad
Please note that declaring a specific individual to have disbelieved and left the fold of Islaam is an affair that is to be returned back to the scholars and it is not for other than them to declare a specific individual to have disbelieved.