The eminent Muslim scholar and renowned Da`iyah, Sheikh `Abdel Khaliq Hasan Ash-Shareef, states: “Al-Khawarij are a group of people who fought against Imam `Ali ibn Abi Talib and claimed that he judged according to people’s laws instead of the ruling of Allah. They had three misconceptions; therefore, Imam `Ali (may Allah be pleased with him) sent for them `Abdullah ibn `Abbas who argued with them and as a result many people among them came back to the truth and a small group did stick to their trend. The later group were known later as Al-Khawarij which had many sects. They see that the one who does major sins is a disbeliever contradicting the opinion of Ahl As-Sunnah wal jama`ah who view that the one who commits a grave sin is not kafir unless he is of the opinion that committing grave sins is lawful which is contradictory to the clear and definite texts of Shari`ah and thus only such a person is considered kafir.
Judging some persons to be from Al-Khawarij is a thorny issue that is not left to individuals. We can say that Al-Khawarij is a deviant group without judging a certain person to be one of Al-Khawarij.
The Khawarij group dates back to the time of Imam `Ali ibn Abi Talib (may Allah be pleased with him) and they shed Muslims’ blood based on a grave and heinous wrong ijtihad (personal reasoning) but it should stressed that no one is to judge a certain person to from the Khawarij.