The beliefs of the Khawarij can be divided into two general categories:
a) Issues related to faith and disbelief. All Khawarij considered the perpetrator of a major sin to be a disbeliever. This issue of belief has very important theological requirements that were usually explained and interpreted in later times. These requirements are:
1 - Action is part of faith and is included in faith.
2 - There is no status between disbelief and faith. Therefore, every human being is either a believer or a disbeliever.
3 - Faith has different degrees, and the degrees of faith depend on the nature of the actions. For example, the faith of a person who abandons all obligatory and all abominable acts is higher than the faith of a person who only acts on obligatory acts.
4 - Since action is part of faith, then any action that contradicts faith causes one to leave the circle of faith. According to the Khawarij, a major sin is an action that contradicts faith and causes disbelief.
5 - Since the perpetrator of a major crime is an infidel, his punishment in the hereafter is eternal and he will remain in the eternal fire.
b) Issues that are not directly related to faith and disbelief. The most important of these opinions are:
1 - Enjoining what is right and forbidding what is wrong is obligatory in all degrees, even if it leads to fighting; they did not recognize any restrictions or conditions for killing and fighting those they consider infidels.
2 - It is obligatory to go out and fight with an unjust ruler.
3 - It is forbidden to establish and accept the judgment of other than God.
4 - If the existence of an Imam is necessary, he is appointed by the free choice of all Muslims, and his Imamate will continue as long as he acts according to justice and principle and does not commit any error.
5 - Imamate and caliphate are also permissible for people other than Quraysh.
6 - They consider Imam Ali (peace be upon him), Uthman, Talha, Zubair, Aisha, and all the caliphs of the Umayyads and Abbasids to be infidels and consider it obligatory to disown them.
