Is every innovator considered an infidel, and what is the ruling on declaring some well-known Sufi scholars to be infidels?

Not every innovator is to be ruled as a disbeliever; some of them are declared disbelievers, and some are declared fasiq (transgressors). The same applies to those who ascribe themselves to Sufism. It is obligatory to guard the tongue from delving into matters of declaring others disbelievers or innovators without proof.