Shaykh Ibn ‘Uthaymeen said: The term Ahl as-Sunnah includes the Mu‘tazilah, includes the Ash‘aris, and includes those followers of innovation whose innovation does not go as far as disbelief, if we use the term to mean as opposed to the Raafidis.
But if we want to explain the meaning of the phrase Ahl as-Sunnah, we say that Ahl as-Sunnah in the true sense of the word are the righteous forebears (as-salaf as-saalih) who united in their adherence to the Sunnah and followed it. In this case, the Ash‘aris, Mu‘tazilah, Jahamis and so on are not among Ahl as-Sunnah according to this meaning.