Therefore from the Shari'ah point of view, anyone who does not have an acceptable Iman is Kafir.
Again in the same work of Ibn Manzur, he mentions Lugat (Grammarian/Language) scholar Zajjaj definition to be as follows:
Since Kufr is the opposite of Iman not submitting to the Shari'ah and to deny/reject anything from the Shari'ah is Kufr as well.
Islam is, actualizing the oneness of Allah, worshiping Him solely, not associating anything to Him, having Iman in Allah and His Rasul (prophet) and subject to things which the Rasul had brought along. The slave who does not actualize these is not Muslim. If this individual who does not actualize these is not a stubborn (meaning the one who rejects knowingly) Kafir then he is an ignorant Kafir. These individuals who are evaluated as ignorant, even though they do not persist against the truth, they go through Kufr because of their ignorance. Not being stubborn does not prevent them from being Kafir. It is because Kafir is the one who rejects the Tawhid of Allah and denies the prophet of Allah; by persistence, by ignorance or by following those who are stubborn. Those Muqallid (blind followers) of the stubborn individuals go through Kufr because of following the stubborn ones although they do not persist. It is obligatory upon a slave to believe that those who do not submit to Islam are Kafir.
Iman in Arabic means belief which is committed to submission. In Islamic terminology its meaning varies according to usage and it may mean one of two things:
1. When the word is used on its own and is not accompanied by the word Islam, it refers to the deen as a whole, as in the verses where Allah says:
Hence the salaf were unanimously agreed that iman means
Hence Allah limited the word iman to those who adhere to His deen in full, inwardly and outwardly, when He says:
And Allah referred to iman as including all of that when He says:
The Messenger of Allah (peace and blessings of Allah be upon him) described fasting the month of Ramadaan out of faith and in the hope of reward as being part of faith; he also said the same concerning spending the night of Laylat al-Qadar in prayer, fulfilling one's trusts, jihad, Hajj, attending funerals, etc.
2. When the word iman is used in conjunction with the word Islam. In this case it is understood as referring to inward beliefs as in the hadeeth of Jibreel etc., and as in the hadeeth of the Messenger of Allah, peace and blessings of Allah be upon him, concerning the funeral du’a:
That is because physical actions can only be accomplished during life, but when one is dying all that is left is the words and actions of the heart.
When either word, iman or Islam, is used alone, there is no difference between them, rather each of them when used alone refers to the entire deen.
If there is any difference between them, then the word Islam refers to outward physical actions and the word iman refers to inward actions of the heart. This is what is indicated by the hadeeth of Jibreel from ‘Umar ibn al-Khattab, radhiAllahu anhu, who said:
The pillars of Iman as Allah jalla wa ‘alaa has obligated are six. The correct belief that Allah accepts is not achieved except by having faith in these pillars, the way Allah wants us to believe in them and not the way our desires or we want. If one of the pillars is deficient or lacking then Allah does not accept this Iman and Islam.
Allah jalla wa ‘alaa says:
Belief in Allah: is the firm conviction and absolute belief that Allah is the Lord, Creator and Master of all things. As He alone is the Creator of the creation so too he alone is the possessor of the right to legislate and lay down laws that regulates their lives; that He alone is worthy of undivided worship (which takes the form of prayers, fasting, supplication, hope, fear, submission and surrender); that He is distinguished by all the attributes of perfection and completeness and that He is above any faults or deficiencies.
Belief in the Angels: this is the firm conviction that Allah’s angels exist; that they are honourable slaves created from light. They do not disobey any of Allah’s commands and they carry out the functions He instructs them to fulfil. They are beings of light, having no physical body that can be discerned by the human senses. They are unlike man in that they don’t eat, drink, sleep, marry or procreate and they are not male or female.
It is a particular obligation to believe in those whose names have been mentioned in Quran and authentic ahadeeth of the Prophet, may Allah bless him and grant him peace, like (Jibreel, Mikaeel, Israfeel, Ridwaan and Maalik) and in the duties and functions entrusted to them like carrying the throne, protection and recording (deeds). As for the angels who have not been mentioned, we should believe in them on the whole and only Allah knows how many there are.
Belief in Divine Scriptures: to believe in the Books that Allah revealed to His Messengers and Prophets, peace and blessings of Allah be upon them all. Allah has mentioned the names of some of these Books to us in the Quran and there are others that He has not mentioned to us. Those that He has informed us about in the Quran, which Allah revealed to Prophet Muhammad, peace and blessings be upon him, are Torah to Musa (Moses); Injeel to Isa (Jesus); Zabur to Dawud (David) and the scriptures revealed to Ibrahim (Abraham) and Musa (Moses), peace and blessings upon all of them.
It is also obligatory to believe that all the Books revealed by Allah been revealed with truth, light, guidance; the Tawhid of Allah in His Lordship, worship, names and attributes. Anything incorporated in them that contradict these aspects has been added and changed by man.
We believe that all the Books excluding the Quran have been changed. As for the Quran Allah has guarded and protected it from alteration, substitution, distortion and corruption. The Quran is the last Book revealed by Allah and its rulings remains till the day of judgement without alteration, substitution and change and that it has been revealed to all man and jinn. It is obligatory that we follow its commands, seek judgement from it in every big and small issue, avoid its prohibitions, believe its accounts and reject anything which contradicts it.
Belief in the books that were revealed before the Quran and were then distorted is to believe that they were originally revealed by Allah but that they no-longer contain the words of Allah, except for what concurs with the Quran and Sunnah of the Prophet, may the peace and blessings of Allah be upon him.
Belief in the Messengers: it is the firm conviction that Allah has Messengers, peace be upon them all, whom He sent to guide the creation in their life in this World and about the hereafter. It is obligatory upon us to believe in everyone of them that is mentioned in the Quran and the Sunnah of the Prophet, may Allah bless him and grant him peace, and the belief that Allah sent others besides them whose numbers and names only He knows.
Belief in The Last Day: it is the firm belief in all that Allah mentions in the Quran, and in all that the Prophet, peace and blessings of Allah be upon him, has informed us, about the afterlife: the fitna of the grave, punishment and reward therein, resurrection, the gathering, the records, the reckoning, the scale, the fount, the bridge ‘as-sirat’, intercession, Paradise and the hellfire and everything which Allah has prepared for those who will dwell in them.
Belief in Al-Qadaa’ wal Qadar (Divine Preordainment) Whether Good or Bad is in the control ofAllah: Allah does not accept ones belief in Qadaa wal Qadar except if he believes in the following four:
1 - Belief in the eternal knowledge of Allah and that He knows the actions of His creation before they do them. Allah has recorded it in the Lawh-al-Mahfuz (the Book of Decree).
2 - The belief that what Allah Wills happens and what He does not Will, will not happen. Any movement or tranquillity that takes place in the heaven or earth is by Allah’s will.
3 - The belief that Allah created all creation, that He is the Creator of everything and all their actions. Everything else besides Allah is created and whatever is in the universe is by the will and preordainment of Allah.
4 - Allah creates all the actions of His servants, but they have a will of their own and act accordingly. The servants have ability to fulfil their actions and they have a will, but Allah created them, their ability and will. To believe that whatever you receive, you would never have missed and whatever you have missed you would have never received it.
Allah jalla wa ‘alaa says:
Man will be held accountable for his actions, if it is good then good will be his reward and if it is bad then bad. Allah subahana wa ta’ala has created in man the ability to know the good from the evil, the truth from falsehood and gave him the freedom to choose.
Allah is not pleased with disbelief for His servants nor does He order His servants to commit kufr (disbelief).
Allah knows what will happen, when it will happen and how it will happen before it happens. Allah subhana wa ta’ala knows before He creates a person how he will be after he is created, whether he will believe or disbelieve or whether he will die upon belief or disbelief.
Everything that has been written down will come to pass as Allah has ordained but this does not mean that Allah has compelled a person to disbelief or to belief because Allah has given his slave the freedom to choose Imaan (faith) or kufr (disbelief). Therefore he will be held accountable for his choice and will be rewarded accordingly.
Increase and Decrease in Iman
Allah's statement:
is similar to His statement:
Bukhari and other scholars relied on this Ayah (i.e., al-Anfal 8/2) and those similar, as evidence that Iman (faith) increases and varies in strength from heart to heart. This is also the view of the majority of the scholars of Islam, prompting some scholars, such as ash-Shafi`i, Ahmad ibn Hanbal and Abu Ubayd to declare that this is the Ijmaa (consensus) of the Ummah (nation of Islam), as we mentioned in the beginning of the explanation of Sahih al-Bukhari. All the thanks and praises are due to Allah.
Allah says:
then among the hypocrites are: some who say: Which of you has had his faith increased by it. They say to each other, who among you had his faith increased by this Surah from the Qur'an. Allah the Exalted says:
This Ayah is one of the mightiest evidences that faith increases and decreases, as is the belief of most of the Salaf (predecessor) and later generations of scholars and Imams. Many scholars said that there is Ijmaa (a consensus) on this ruling. We explained this subject in detail in the beginning of the explanation of Sahih al-Bukhari, may Allah grant him His mercy.
From this and other similar Ayaat, several scholars, such as al-Bukhari and others, understood that faith may increase, that it may vary in degrees, and that it may fluctuate. Allah says:
as He says elsewhere:
There are other Ayaat indicating the same thing.
