Are the Khawarij and the Ibadhiyyah disbelievers?

Question:
Are the Khawarij disbelievers?

Answer:
The well-known view among scholars is that they are sinners, but the view that they are disbelievers is more evident in the evidence. This is because the Messenger of Allah (peace and blessings be upon him) said regarding them: "They will emerge from Islam and then not return to it." The apparent meaning of the Sunnah is that they are disbelievers. They are the ones who declare the Companions disbelievers and accuse them of open sinfulness, and who declare the people of major sins disbelievers and believe that they will remain in the Fire forever. These are vile, false beliefs, and the statement of those who declare them disbelievers is the stronger one.
Q: Are the Ibadhiyyah, O Shaykh, of the same type as the old Khawarij?
A: They are from the remnants of the Khawarij, but they do not openly declare sinners to be disbelievers. However, they say that they will remain in the Fire forever; the sinner remains in the Fire forever, following the method of the Khawarij and the Mu'tazilah.
In any case, they follow the method of the Khawarij and the Mu'tazilah in believing that sinners will remain in the Fire forever, but they may not explicitly declare the sinner a disbeliever. They also deny the vision of Allah—seeing Allah on the Day of Resurrection and in Paradise. Their statement is vile.