Clarification that disbelief is divided into two categories: practical and creedal.

The Shaykh : So, whoever among the Muslim rulers is in the position of the Jews and Christians who do not believe in the rulings of Islam, his disbelief is apostasy and has nothing to do with Islam. But whoever’s disbelief is practical disbelief—meaning he believes that these rulings are the truth and are the Shari'ah, and that they should be implemented, but he finds an excuse for himself, even though it is not an excuse in the Shari'ah—the important point is that he acknowledges these Shari'ah rulings, but he does not implement them. Ibn 'Abbas calls the disbelief of this type of ruler practical disbelief. Why? This is a very important reality because it differs from those who deny ruling by what Allah has revealed in their hearts and on their tongues. If we find a person of this type who denies the Shari'ah of Allah and the rulings of Allah with his tongue and his heart, then he is certainly not a Muslim. If we find another person who testifies and acknowledges that this is Islam and that it should be implemented, but practically he does not implement it, then there is a similarity between him and the first category in terms of practice. Those people disbelieved in it with their hearts and denied it—also—with their actions. As for this Muslim, he acknowledged the ruling of Allah (Mighty and Majestic) in his heart, but he did not implement it with his action. So, in his action, he does the action of a disbeliever. Therefore, this reality becomes clear to you when you hear in the sermon of the Messenger (peace and blessings be upon him) during the Farewell Pilgrimage. Among the things he preached to the Companions of the Prophet (peace and blessings be upon him), admonishing and reminding them, he said to them: . What does "disbelievers" mean? Does it mean atheists? Does it mean you deny the Shari'ah of Allah after you have believed in it and acted upon it? No, that is not the intended meaning. Rather, it means do not return after me as disbelievers in your actions, doing the actions of disbelievers, striking the necks of one another. This is the meaning of "disbelievers" here in this hadith.
Similarly, for example, the saying of the Messenger (peace and blessings be upon him) in the authentic hadith: , , is like his saying in the hadith before it: . Fighting is disbelief; meaning: the action of disbelievers who, despite being in one religion, do not prevent some of them from killing others. So do not do the action of disbelievers. . Therefore, the scholars say: "Disbelief is of two types: creedal disbelief and practical disbelief." Whoever disbelieves with creedal disbelief is not among the Muslims. Whoever disbelieves with practical disbelief, meaning he does the action of disbelievers, but he does not consider it permissible in his heart, and he does not say: "This is lawful." Rather, he acknowledges that it is forbidden, but: "May Allah curse the devil," as the sinners say.
Therefore, you must know that if we do not distinguish between the one who considers sin permissible in his heart and the one who considers sin permissible in his action without his heart, there will be no Muslim left except that you should rule that he is a disbeliever. Why? When a thief steals, do we declare him a disbeliever? Theft and zina and the like are like killing; both are forbidden. If the Messenger (peace and blessings be upon him) said that a Muslim fighting his Muslim brother is disbelief, and it is not interpreted as creedal disbelief, but rather as practical disbelief, then if a Muslim commits zina, is he a disbeliever with apostasy? The answer: It is necessary to distinguish. This fornicator, that thief, that liar, and every person who commits a sin, it is necessary to distinguish between the case where he considers it permissible in his heart, in which case he is a disbeliever who has apostatized from his religion, and the case where he does not consider it permissible in his heart, but he considers it permissible in his action; so he does the action of disbelievers who do not declare things lawful or forbidden. So, the one who considers sin permissible in his action, not in his heart, is a Muslim who is an open sinner, not a disbeliever; because he has not disbelieved in Allah and His Messenger in his heart and his belief. This is what must be distinguished so that we do not suffer what befell the Khawarij before, who fought 'Ali ibn Abi Talib because they declared Muslims disbelievers merely on the assumption that they ruled by other than what Allah revealed. If only they had been correct that they ruled by other than what Allah revealed. So he (peace be upon him) said regarding these people: .