The Ash'arites are misguided heretics,
Brothers of those who worshipped al-ʿUzzā along with al-Lāt.
In their Lord they have committed Disbelief openly, and their statement,
If you ponder it, is the worst of statements.
They negate what they affirmed, returning to their beginning,
The beliefs of the people are among the flimsiest of absurdities (1).
The rationale of those among the people of the Sunna who went to the extent of declaring them disbelievers is that they looked at the reality of the Ash'arite school of law and their roots upon which they built their school of law in creed, and they found them taken from the roots of the Jahmīs, whom the predecessors unanimously agreed upon declaring as disbelievers.
Among those roots is the early Ash'arites' denial of the voluntary actions of God Almighty.
Ibn Taymiyya, may Allah have mercy on him, said in Minhāj al-Sunna (2/390): (And al-Ashʿarī is a follower in that of the Jahmīs and the Mu'tazilites who denied the subsisting of action in Him, Almighty; however, those also deny the attributes, unlike the Ash'arites). End quote.
So this is with respect to the early Ash'arites.
As for their later ones, they allied with the Jahmīs and the Mu'tazilites, so the reality of their inner state was the inner state of the denuding Jahmī Mu'tazilites.
