Ruling on one who rejects a saheeh hadith
Question

Does the one who rejects a saheeh hadith become a disbeliever? One of the brothers rejects some of the saheeh hadiths that are narrated in al-Bukhaari, Muslim and elsewhere, on the grounds that they contradict the Quran. What is the ruling on one who rejects a saheeh hadith? Does he become a disbeliever?
Praise be to Allah.Firstly: 
The Prophet’s Sunnah is the second source of Islamic sharee‘ah. The revelation came down to the Prophet (blessings and peace of Allah be upon him) with the Sunnah as it came down to him with the Qur’an. The proof of that is the words of Allah, may He be exalted (interpretation of the meaning):
“Nor does he speak of (his own) desire.
It is but a revelation revealed”
[an-Najm 53:3-4]. 
Allah, may He be exalted, has enjoined upon the believers complete submission to the words of the Prophet (blessings and peace of Allah be upon him) and his hadith and rulings, to the extent that He, may He be glorified, swore by His divine self that whoever hears the words of the Prophet (blessings and peace of Allah be upon him), then rejects them and does not accept them, has nothing to do with faith at all. He, may He be glorified and exalted, said (interpretation of the meaning):
“But no, by your Lord, they can have no Faith, until they make you (O Muhammad (blessings and peace of Allah be upon him)) judge in all disputes between them, and find in themselves no resistance against your decisions, and accept (them) with full submission”
[an-Nisa’ 4:65]. 
Hence there was consensus among the scholars that whoever denies that the Sunnah constitutes shar‘i evidence in general terms, or rejects a hadith of the Prophet (blessings and peace of Allah be upon him – knowing that it is the words of the Prophet (blessings and peace of Allah be upon him) – is a disbeliever, who has not attained even the lowest level of Islam and submission to Allah and His Messenger. 
Imam Is-haaq ibn Raahawayh (may Allah have mercy on him) said:
Whoever hears a report from the Messenger of Allah (blessings and peace of Allah be upon him) that he accepts as being sound, then rejects it, not by way of dissimulation (when he has no choice because of a threat), is a disbeliever. End quote 
As-Suyooti (may Allah have mercy on him) said: 
You should understand, may Allah have mercy on you, that whoever denies that the hadith of the Prophet (blessings and peace of Allah be upon him) constitutes shar‘i evidence – whether he denies a report that speaks of something that the Prophet (blessings and peace of Allah be upon him) said or did, if that hadith fulfils the conditions stipulated in usool al-hadith – has committed an act of disbelief that puts him beyond the bounds of Islam, and he will be gathered (on the Day of Resurrection) with the Jews and Christians, or with whomever Allah wills of the disbelieving groups. End quote. 
Miftaah al-Jannah fi’l-Ihtijaaj bi’s-Sunnah (p 14) 
Al-‘Allaamah Ibn al-Wazeer (may Allah have mercy on him) said:
Rejecting the hadith of the Messenger of Allah (blessings and peace of Allah be upon him) when one is aware that it is his hadith constitutes blatant disbelief. End quote. 
Al-‘Awaasim wa’l-Qawaasim (2/274) 
It says in Fataawa al-Lajnah ad-Daa’imah: 
The one who denies that we should follow the Sunnah is a disbeliever, because he is expressing disbelief in Allah and His Messenger, and rejecting the consensus of the Muslims. End quote. 
Fataawa al-Lajnah ad-Daa’imah (vol. 2, 3/194) 
See also the answers to questions no. 604, 13206 and 77243 
Secondly: 
As for the one who rejects a hadith and does not accept it, denying that it is the words of the Prophet (blessings and peace of Allah be upon him), he is not like those who come under the first category. We understand that many followers of the new “enlightenment” trend – who have taken it upon themselves to judge the Prophet’s Sunnah on the basis of their views and affiliation – in fact, have not come up with anything new. Rather they are a continuation of the innovators who came before them, whose specious arguments the scholars quoted and took it upon themselves to refute them. 
To these people and others like them we say: 
Academic methodology dictates that we should examine several important matters before rejecting a hadith or denying that it is the words of the Prophet (blessings and peace of Allah be upon him). These conditions are as follows: 
The first condition: 
We should see whether there is a complete contradiction between what is mentioned in the hadith and what is mentioned in a Qur’anic text that is clear and unambiguous in meaning and not abrogated. We should emphasise here the condition of complete contradiction – and not just an apparent contradiction that may come to the mind of one who hastens to jump to conclusions when examining hadith. Perhaps those who are involved in denying the hadiths will agree with us on this condition, because most of the apparent contradictions that occur to many people are not contradictions in reality; rather they are mere speculation in the mind of the objector and it is possible, with deliberation and by examining the shades of meaning of different words, to answer the one who thinks that there is a contradiction, and demonstrate how the hadith is in harmony with the fundamentals and sublime aims of sharee‘ah. Whoever studies the book of al-‘Allaamah Ibn Qutaybah ad-Deenoori entitled Mukhtalif al-Hadith will realise how reckless many of them were in their denial of hadiths on the basis of the claim that they are not in accordance with the Qur’an, or that they contradict sound reasoning, but when Ibn Qutaybah mentions the correct explanation of these hadiths given by the scholars, it becomes clear that there is a sound interpretation for them that is in harmony with Islamic teachings, and that the notion that these hadiths contradict the Quran is based on corrupt understanding. 
We ask these people and their ilk, who have the audacity to reject the Sunnah and cast aspersions on the hadiths of the Prophet (blessings and peace of Allah be upon him) without any academic methodology or acceptable critical guidelines, and without properly understanding the fundamentals of hadith science that they are talking about, the following: 
Do you think that it is possible for a hadith to completely contradict the Holy Qur’an to the extent that the examiner may think that this hadith is not the words of the Prophet (blessings and peace of Allah be upon him), at the time when we see all the scholars of Islam, from the time of the Companions of the Messenger of Allah (blessings and peace of Allah be upon him) up until the present day, in agreement on accepting this hadith and commenting on it, interpreting it, quoting it as evidence and acting upon it? 
Doesn’t rational thinking – on which they claim to base their argument – dictate that they should respect the consensus of specialists on the matter that is at the heart of their specialty? 
Can anyone have the audacity to say that physicists, chemists, mathematicians, educationalists or economists, for example, have made a mistake if they agree on a matter – especially when the one who is objecting to them is not one of the specialists in that field; rather all that can be said is that he has read some articles about it or a few books along the lines of Science For Dummies or The Complete Idiot’s Guide to Science [i.e., books that offer a basic introduction to a field]? 
The second condition: 
There should be a weakness in one of the links of the isnaad that could have led to the mistake mentioned in the text. 
Similarly, we think that this condition is in harmony with sound methodology and is a valid condition. No one should disagree on this point who understands anything about the principles of academic criticism. Denying that a text is the words of the Prophet (blessings and peace of Allah be upon him) should mean that there is a weak link in the chain of narration that led us to mistakenly believe that this hadith is the words of the Prophet (blessings and peace of Allah be upon him), when in fact it is not. 
Imam ash-Shaafa‘i (may Allah have mercy on him) – who is prominent in terms of knowledge and faith, and was the first one to write on the topic of usool al-fiqh – said: 
If a hadith is narrated by trustworthy narrators from the Messenger of Allah (blessings and peace of Allah be upon him), then that is sufficient to regard it as a sound hadith. 
Ikhtilaaf al-Hadith, in al-Umm (10/107). 
And he said: 
There is no other way to determine whether a hadith is sound or otherwise except by knowing how honest and trustworthy the narrators are, with the exception of very few hadiths. 
Ar-Risaalah (para. 1099) 
And he also said: 
Muslims of good character are those who are good and sound in and of themselves… As for what they say and do, it is to be regarded as sound and acceptable, unless we find something in their actions that indicate otherwise. So we should be cautious with them in cases where their actions differ from what is expected of them. 
Ar-Risaalah (para. 1029-1030); see also al-Umm (8/518-51 9) 
After narrating some of the academic principles concerning this matter, which is something that he discussed a great deal in his various books, Imam ash-Shaafa‘i (may Allah have mercy on him) says that what he stated – some of which we have quoted here – is not the view of only a few scholars, or his own personal view; rather these are the principles on which there was consensus among the scholars who came before him. He says: 
At the beginning of this book of mine, I quoted, in support of what I discuss of principles and guidelines, from a number of earlier scholars who had knowledge of the Qur’an and Sunnah, different scholarly opinions, analogy and rational thinking, and none of them differed with another. They said: This is the view of the scholars among the Companions of the Messenger of Allah, the Taabi‘een, and the generation who followed them, and it is our view. Whoever diverges from this path is, in our view, diverging from the path of the Companions of the Messenger of Allah (blessings and peace of Allah be upon him) and the path of the scholars who came after them, until the present day, and he is one of the people of ignorance. And all of them said: we cannot see anything but the consensus of the scholars in all regions, unanimously agreeing to regard as ignorant the one who departs from this path. And they – or most of them – went even further and expressed more stringent views with regard to the one who departs from this path, but there is no need to quote them here. 
Ikhtilaaf al-Hadith, al-Umm (10/21). See also: ar-Risaalah (para. 1236-1249). 
The first thing that the one who rejected a hadith that is attributed to the Prophet (blessings and peace of Allah be upon him) must do is research and find out the identity of the narrator who was mistaken in his transmission of this hadith. If the one who denies the hadith cannot find an acceptable reason in the isnaad for rejecting the hadith, then this indicates that he is mistaken in his methodology. It also indicates that it is essential to have another look and try to understand the hadith and the Qur’an and the aims and goals of sharee‘ah. 
So how about if the hadith was narrated with the soundest isnaads on the face of the earth? How about if the hadith was narrated via many chains of transmission – as is the case with most of the hadiths that are rejected by the proponents of “enlightenment” – and from a number of the Sahaabah (may Allah be pleased with them)?  
The third condition: 
One should express his reservations about a hadith as a personal view based on his own reasoning, which may be right or wrong, and he should avoid stating his view as certainty, as if it is the correct view. He should also avoid making accusations against others who differ with him or casting aspersions on the intelligence of Muslim scholars. This applies in cases where there is a valid reason to hold such a view, and provided that one is qualified to speak about such matters and is proficient in the skills needed to understand and research them. A hadith may appear to be da‘eef (weak) to one scholar for a particular reason, but he should not speak in accusatory tones of those who accepted the hadith. 
Whoever does not comply with these three conditions and persists in denying and rejecting the hadiths is exposing himself to grave danger, because it is not permissible for a Muslim to reach a conclusion that is not based on proper methodology and without following any guidelines, and criticise other scholars (who disagree with him), otherwise he may fall into sin and error. 
Imam Ahmad (may Allah have mercy on him) said: Whoever rejects the hadith of the Messenger of Allah (blessings and peace of Allah be upon him) is on the brink of doom. End quote. 
Al-Hasan ibn ‘Ali al-Barbahaari said: 
If you hear a man casting aspersions upon a hadith or denying a hadith, or giving precedence to something else over a hadith, then suspect his commitment to Islam, for he is undoubtedly following whims and desires and innovation. 
If you hear a man, when you quote a hadith, showing no interest in it on the basis that he only wants to hear quotations from the Qur’an, you should not doubt that he is a man who is following the path of the heretics, so get up and leave him, and bid him farewell. End quote.
Sharh as-Sunnah (113-119)
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
Whatever the Messenger (blessings and peace of Allah be upon him) narrates from his Lord, it is obligatory to believe in it, whether we understand its meaning or not, because he is the most truthful one [namely the Prophet (blessings and peace of Allah be upon him)]. Whatever it says in the Qur’an and Sunnah, every believer must believe in it, even if he does not understand its meaning. End quote.
Majmoo‘ al-Fataawa (3/41)
See also the answers to questions no. 245, 9067 and 20153
And Allah knows best.