What is the fate of the blood shed between two warring factions, each believing itself to be in the right and defending its religion and homeland, and what is the stance of its shedder on the Day of Judgment, by analogy with what happened in the strife between Ali and Mu'awiyah?

Armed conflict in Muslim countries cannot involve both parties seeking to protect religion and the homeland. Some parties adopt Islam and the interests of the homeland, while others fight Islam and pursue private interests. If two sincere parties differ on matters of religion, then it is obligatory for them to engage in dialogue and present Sharia-based evidence. If there is a Muslim ruler, the people of authority (Ahl al-Hall wal-Aqd) must advise him and incite him to act according to Sharia. It is not permissible to rebel against him unless he shows clear disbelief (kufr bawwah). Imams whom people dislike and revile, it is not permissible to rebel against them as long as they establish prayer. If they see from them what they dislike, they should dislike the act but not withdraw their hand from obedience. It is not permissible for any group to pledge allegiance to another person to fight a just Imam; rather, it is obligatory to support the just Imam. As for an oppressive Imam, if a just Imam rebels against him and it is possible to support him without great corruption, then supporting justice becomes obligatory. However, if that would lead to great tribulation (fitna), then patience with his oppression is obligatory. If two oppressive rulers fight each other, it is not permissible to participate with either of them; rather, they should be left for Allah to take vengeance on one by means of the other. It is not permissible for Muslims to fight each other over worldly matters, and the killer and the killed over worldly matters are in Hellfire. What transpired between the Companions in the Battle of the Camel and Siffin was an act of ijtihad (independent reasoning) on their part, and it is obligatory to think well of them and to refrain from discussing their disputes.