Do the Khawarij declare people disbelievers for sins?

Question:
Q: Do the Khawarij declare people disbelievers for sins?

Answer:
Allah knows best. It is well known that they declare people disbelievers for sins, and some of them report that they do so for major sins. This requires careful examination of their books. Their books are available, and they have remnants today in Oman, in Algeria, and in Libya. They have remnants, and they are the Ibadis. However, the later ones among them seem to have softened somewhat. We met with some of them, and they say: We do not say: disbeliever, but rather one who will remain in the Fire forever. It seems they leaned toward the view of the Mu'tazilah, and the meaning is the same; if they say: one who will remain in the Fire forever, its meaning is that he is a disbeliever.
... The well-known view among scholars is that they say they declare people disbelievers for sins absolutely, but perhaps they mean the sins that carry a threat, such as major sins.