Justification for following the Sunnah
Question

 
Why do we have to follow the sunnah of the prophet Muhammad and not just follow the quran ?
Why do we have to follow a specific Mathab?
Praise be to Allah.The first question may appear strange and somewhat surprising to committed, practising Muslims. How can something which is so obviously one of the bases of Islaam become a matter for discussion and debate? But since the question has been asked, we will present, with the help of Allah, the principles and bases of the importance of the Sunnah, the obligation to follow it and the ruling concerning those who reject it. By so doing, we will also refute the doubters and the misguided group who call themselves “Quraniyyeen” (the Quran has nothing to do with them!) In sha Allah this discussion will be of benefit to everyone who wants to understand the truth of the matter.
Proof of the importance of the Sunnah
(1) The Quran speaks of the importance of the Sunnah, for example:
(a) Allah says (interpretation of the meaning): “He who obeys the Messenger has indeed obeyed Allah . . .” [al-Nisaa’ 4:80] Allah described obedience to the Prophet (peace be upon him) as being a part of obedience to Him. Then He made a connection between obedience to Him and obedience to the Prophet (peace be upon him): “O you who believe! Obey Allah and obey the Messenger . . .” [al-Nisaa’ 4:59]
(b) Allah warns us not to go against the Prophet (peace be upon him), and states that whoever disobeys him will be doomed to eternal Hell. Allah says (interpretation of the meaning): “. . . And let those who oppose the Messenger’s commandment beware, lest some fitnah (trial, affliction, etc.) befall them or a painful torment be inflicted on them.” [al-Nur 24:63]
(c) Allah has made obedience to His Prophet a religious duty; resisting or opposing it is a sign of hypocrisy: “”But no, by your Lord, they can have no Faith, until they make you [Muhammad] judge in all disputes between them, and find in themselves no resistance against your decisions, and accept (them) with full submission.” [al-Nisaa’ 4:65]
(d) Allah commands His slaves to respond to Him and His Messenger: “O you who believe! Answer Allah (by obeying Him) and (His) Messenger when he calls you to that which will give you life . . .” [al-Anfaal 8:24]
(e) Allah also commands His slaves to refer all disputes to him: “. . . (And) if you differ in anything amongst yourselves, refer it to Allah and His Messenger . . .” [al-Nisaa’ 4:59]
(2) The Sunnah itself indicates the importance of the Sunnah. For example:
(a) Al-Tirmidhi reported from Abu Raafi’ and others that the Prophet (peace be upon him) said: “I do not want to see any one of you reclining on his couch and, when he hears of my instructions or prohibitions, saying ‘I don’t accept it; we didn’t find any such thing in the Book of Allah.’” Abu ‘Eesaa said: This is a saheeh hasan hadeeth. (See Sunan al-Tirmidhi, Shaakir edition, no. 2663).
Al-’Irbaad ibn Saariyah, may Allah be pleased with him, reported that the Prophet (peace be upon him) said: “Would any of you think, reclining on his couch, that Allah would only describe what is forbidden in the Quran? I tell you, by Allah, that I have warned and commanded and prohibited things that are as important as what is in the Quran, if not more so.” (Reported by Abu Dawud, Kitaab al-Khiraj wa’l-imaarah wa’l-fay’).
(b) Abu Dawud also reported from al-’Irbaad ibn Saariyah, may Allah be pleased with him, that “the Messenger of Allah (peace be upon him) led us in prayer one day, then he turned to us and exhorted us strongly . . . (he said), ‘Pay attention to my sunnah (way) and the way of the Rightly-guided Khaleefahs after me, adhere to it and hold fast to it.’” (Saheeh Abi Dawud, Kitaab al-Sunnah).
(3) The scholars’ consensus (ijmaa’) affirming the importance of the Sunnah.
Al-Shaafi’i, may Allah have mercy on him, said: “I do not know of anyone among the Sahaabah and Taabi’een who narrated a report from the Messenger of Allah (peace be upon him) without accepting it, adhering to it and affirming that this was sunnah. Those who came after the Taabi’een, and those whom we met did likewise: they all accepted the reports and took them to be sunnah, praising those who followed them and criticizing those who went against them. Whoever deviated from this path would be regarded by us as having deviated from the way of the Companions of the Prophet (peace be upon him) and the scholars who followed them, and would be considered as one of the ignorant.
(4) Common sense indicates the importance of the Sunnah.
The fact that the Prophet (peace be upon him) is the Messenger of Allah indicates that we must believe everything he said and obey every command he gave. It goes without saying that he has told us things and given instructions in addition to what is in the Quran. It is futile to make a distinction between the Sunnah and the Quran when it comes to adhering to it and responding to it. It is obligatory to believe in what he has told us, and to obey his instructions.
The ruling concerning those who deny the importance of the Sunnah is that they are kaafirs, because they deny and reject a well-known and undeniable part of the religion.
As regards your second question, about whether a Muslim is required to follow a particular madhhab, the answer is that he does not have to. For the average “rank and file” Muslim, his madhhab is that of his mufti or the scholar whom he consults for religious verdicts; he must ask those pious scholars whom he trusts for opinions when necessary. If a person has enough knowledge to distinguish which evidence and opinion is stronger, then he must follow the scholarly opinion which has the strongest support from the Quran and Sunnah. It is acceptable for a Muslim to follow one of the four well-known madhhabs, on the condition that he understands that the truth in any given issue may lie with another madhhab, in which case he must ignore his own madhhab’s opinion and follow the truth. The Muslim’s aim is to follow the truth that is in accordance with the Quran and Sunnah. The madhhabs of fiqh are only a means of reaching ahkaam (rules) based on the Quran and Sunnah, they are not Quran and Sunnah.
We ask Allah to show us the truth and help us to follow it, and to show us falsehood and help us to avoid it. May Allah bless our Prophet Muhammad.