As for major unbelief, it is of five kinds: unbelief of denial, unbelief of arrogance and refusal to submit even while admitting the truth, unbelief of evasion, unbelief of doubt, and unbelief of hypocrisy.
As for unbelief of denial, it means [truly] believing that the messengers of Allah have lied. This kind of unbelief is uncommon among the unbelievers. This kind of unbelief is uncommon because Allah has assisted His messengers and granted them clear proofs and signs that establish the proof and remove any excuse.
The Almighty said of Pharaoh, โAnd they disputed [Allahโs signs] in vain, even as their [inner] selves believed them, in transgression and prideโ [27:14], and He said to his Messenger ๏ทบ, โIn truth, it is not you they deny [O Muhammad]; rather, the evil-doers flout the revelations of Allahโ [6:33]. [Although the unbelief mentioned in this verse properly belongs to the next category,] if it is labelled the unbelief of denial, that would be correct as well, for it is denial by the tongue.
As for the unbelief of refusal and arrogance, an example of it is the unbelief of Ibliฬs who did not reject Allahโs command in denial, yet he committed unbelief by arrogantly refusing to obey Allah. Likewise is the case of anyone who has known the truthfulness of the messenger and that he has brought the truth from Allah, yet does not obey him due to obduracy and arrogance. This kind of unbelief is the predominant one among the enemies of the messengers, as Allah reports the words of Pharaoh and his people, โShall we believe two mortals like us, while their nation is in our servitude?โ [23:47]. Similarly, other nations said to their messengers, โYou are only mortals like usโ [14:10]. Also, His saying, โThe Thamuฬd denied in their rebellious prideโ [91:11]. This is also the unbelief of the Jews, as the Almighty said, โWhen what they knew came to them, they rejected himโ [2:89], and โThey know him [the Prophet or the Qurสพan] as they know their own sonsโ [2:146]. The unbelief of Abuฬ Tฬฃaฬlib [the Prophetโs uncle] is also of the same nature, for even as he confirmed his [nephewโs] truthfulness and had no doubt about it, his pride and veneration of his forefathers so over- came him that he refused to turn away from their religion and testify to their unbelief.
The unbelief of evasion is to avoid hearing or taking to heart what the messenger says, neither confirming nor denying it, and failing to pay it heed at all. For example, a man from Banuฬ สฟAbd Yaฬliฬl said to the Prophet ๏ทบ, โBy Allah, I shall not say a word to you. If you are truthful, then you are too sublime in my eyes for me to respond, and if you are a liar, then you are too low for me to even talk to.โ
As for the unbelief of doubt, it is to be certain neither of [a messengerโs] truthfulness nor falsehood, but to entertain doubt in his matter. Such a doubt does not persist unless one forces himself to avoid reflecting on the signs of [the messengerโs] truthfulness, neither listening to them nor paying attention. For if one turns to them and reflects [sincerely upon them], doubt cannot persist, as they necessarily reveal their truth, especially if one considers [the signs] altogether, as their truth is clear as the daylight.
As for the unbelief of hypocrisy, it is to proclaim faith verbally but deny it in the heart. This is the greatest kind of hypocrisy, whose types will be explained, Allah willing.
The unbelief of denial is of two kinds: general, unqualified unbelief and limited, qualified unbelief.
The total or unqualified unbelief is to deny the entirety of what Allah has revealed and the message of the Messenger.
The partial or qualified unbelief is to deny one of the obligations or prohibitions of Islam, or one of the attributes with which Allah has characterized Himself, or any teaching that Allah has declared, either intentionally or by preferring the saying of another who has opposed the report for any reason whatsoever.
As for the denial due to ignorance or excusable [erroneous] interpretation, such a person cannot be excommunicated (i.e., declared unbeliever), like in the tradition of one who denied Allahโs power over him, and commanded his people to cremate him and spread him into the winds. Yet, Allah forgave him despite that and had mercy on him due to his ignorance, as he acted in accordance with the best of his knowledge, but did not deny Allahโs power to bring him back to life due to obstinate rejection or denial.
Ibn Qayyim al-Jawziyyah, Madarij al-Salikin Ranks of the Divine Seekers Vol 1 p708-710