الحمد لله وحده، والصلاة والسلام على من لا نبي بعده، وعلى آله وصحبه، أما بعد
Shaikh ul Islaam Ibn Taymiyyah (rahimahullaah) said:
“Rather anyone who observes that which the Khawaarij and the Murji-ah say in regard to the meaning of Eemaan comes to know out of necessity that it is in opposition to the Messenger and knows out of necessity that obedience to Allaah and His Messenger is from the perfection of Eemaan, and that not everyone who commits a sin has been made to become a disbeliever, and he knows likewise that if it were the case that a people were to have said to the Prophet (sallallaahu ‘alaihi wa sallam):
‘We believe in that which you came to us with by way of our hearts – without there being any doubt, and with our tongues we acknowledge the shahaadatayn (the two statements comprising the testimony of faith) – except that:
We shall not obey you in anything from that which you command with and forbade from.
Thus we will not pray.
And not fast.
And not perform the Hajj.
And not be truthful in speech.
And not fulfill the trust.
And we shall not fulfill the pledge.
And we shall not honour and maintain the ties of kinship.
And we shall not do anything from good which you have commanded with.
And we shall drink wine.
As well as marry those that are closely related (through incestuousness) with clear fornication.
And we shall fight and thus kill those that we are able to from your companions and your Ummah and we shall take their wealth; rather we will fight you also – and fight against you along with your enemies.’
Can the intelligent one even imagine that the Prophet (sallallaahu ‘alaihi wa sallam) would say to them: ‘you are believers with complete Eemaan, and you will be from the people of my intercession on the Day of Resurrection and it is hoped for you that none of you shall enter the Fire.’
Rather every single Muslim necessarily knows that he would say to them: ‘you are from the most disbelieving of the people in regard to that which I came with.’ And he would strike their necks if they did not repent from that.”
(Taken from: Majmu’ Fataawa vol 7 p.287)
 Those that oppose Ahlus Sunnah in this issue due to their being two innovated extremist sects are: the Murji-ah as well as the Khawaarij – along with the Mu’tazilah – as stated by Shaikh ‘Uthaimeen (Sharh Al-‘Aqeedah Al-Waasitiyyah p.575-576) hence their mention above due to their extremes.
Shaikh ul Islaam Ibn Taymiyyah stated the origins of the incorrect beliefs of these groups elsewhere when speaking of the incorrect belief of the Khawaarij who stated that one who commits a major sin is a disbeliever, and the belief of the Mu’tazilah who agreed with them in the cessation of all of his Eemaan and his Islaam and that he is to remain forever in the Fire, but differed with them in what he was to be termed; hence they did not call him a kaafir (disbeliever) but stated instead: he is a faasiq (sinner/evil-doer) not a mu’min (believer) and not a kaafir (disbeliever) – to be categorized in a place between two places. After pointing this out, Shaikh ul Islaam said: “The basis of these people is that they thought that a single individual cannot be eligible for reward and punishment, as well as promise and threat, and praise and dispraise. Rather; it has to either be to this or to that; and so they thwart all of his good deeds due to a major sin which he committed, and they say: Eemaan is obedience, thus it ceases with the cessation of some of the obedience. Then they differed as to whether it is followed by disbelief into two sayings; and the Murji-ah and the Jahmiyyah agreed with them in that: Eemaan ceases in its entirety with the cessation of something of it; and that it does not become parts/portions nor does it vary in amount, so it does not increase nor decrease and they said that the Eemaan of the faasiq is like the Eemaan of the Prophets and the believers.” (Sharh Al-Asbahaaniyyah p.658)
He said likewise: “Indeed; there ensnared these people – all of them; i.e. the Murji-ah in all of their varying types; that which ensnared the Khawaarij and the Mu’tazilah in their supposition that Eemaan does not become parts/portions. Rather; if some of it goes then all of it goes, whilst the Madhab of Ahlus-Sunnah wal Jamaa’ah is that it does become parts/portions and that it does decrease and that all of it does not cease to be.” (Sharh Al-Asbahaaniyyah p.671)
Note: The correct belief held by Ahlus-Sunnah in regard to Eemaan is as stated by Shaikh ul Islaam in his book: Al-‘Aqeedah Al-Waasitiyyah when he said: “And from the fundamental principles of Ahlus-Sunnah wal Jamaa’ah is that the religion and Eemaan is statement and action, the statement of the heart and the tongue, and the action of the heart and the tongue and the limbs.” For an elaboration of this refer to: Sharh Al-‘Aqeedah Al-Waasitiyyah by Shaikh ‘Uthaimeen (p.573 onwards).
Shaikh Rabee’ bin Haadi Al-Madkhali (hafidhahullaah) said: “We profess religiousness to Allaah with the fact that Eemaan is: statement and action and belief, it increases with obedience and decreases with sin, the Book of Allaah and the Sunnah of His Messenger (sallallaahu ‘alaihi wa sallam) have proven that. This rule and this definition of Ahlus-Sunnah is a thorn in the necks of the Murji-ah and the Khawaarij and the Mu’tazilah, its supporting foundations are texts which cannot be enumerated from the Book of Allaah and from the Sunnah of the Messenger of Allaah (sallallaahu ‘alaihi wa sallam). This has been proven by the Book of Allaah and the Sunnah of the Messenger of Allaah (sallallaahu ‘alaihi wa sallam) – and it is that which the companions and the Taabi’oon and the Imaams of Islaam proceeded upon until this day of ours.” (excerpt taken from an audio lecture entitled: Ath-Thabaat ‘ala as-Sunnah)
 Declaring Muslims to be disbelievers on the basis of their committing major sins is not from the methodology of Ahlus Sunnah and is contrary to the correct teachings of Islaam, as is explained by Shaikh Saalih Al-Fawzaan (hafidhahullaah) who stated: “As for the madhab of Ahlus Sunnah, then they say; the believer who commits a major sin from the various major sins, then it is not to be said of him that he is complete in Eemaan. Rather he is deficient in Eemaan, and those who say he is complete in Eemaan then they are the Murji-ah who say: ‘sins do no harm when there is Eemaan – just as obedience does not benefit when there is kufr (disbelief).’ In that they are in opposition to the Khawaarij and the Mu’tazilah who say that he is outside the fold of Eemaan; so they are on two opposed views. Hence the madhab of Ahlus Sunnah is the moderate/middle course in this affair, so they do not say: that he is complete in Eemaan – as is said by the Murji-ah, nor do they say: he is a disbeliever – as is said by the Khawaarij, likewise that he is not in a place between two places – as is said by the Mu’tazilah. Rather they say he is a believer – deficient in Eemaan, a believer due to his Eemaan and a sinner due to his major sin, he is to be loved from an aspect and disliked from an aspect. If he dies and does not repent; then his affair is with Allaah, The Glorified and Most High, so he is under the will (of Allaah) – if He Wills; He will forgive him and if He Wills; He will punish him. Then he will come out of the Fire after that, as He, The Glorified and Most High, said:
إِنَّ اللَّهَ لَا يَغْفِرُ أَن يُشْرَكَ بِهِ وَيَغْفِرُ مَا دُونَ ذَٰلِكَ لِمَن يَشَاءُ
((Indeed, Allaah does not forgive Shirk [association in worship] being made with Him, but He forgives what is other than that for whom He wishes.)) (An-Nisaa: 48)”
(Muhaadaraat fil ‘Aqeedah wad-Da’wah vol 3 p.384)