Praise be to Allaah, and blessings and peace be upon His Messenger and his family and companions.
Firstly: the four madhhabs are named after the four imams – Imam Abu Haneefah, Imam Maalik, Imam al-Shaafa’i and Imam Ahmad.
Secondly: These imams learned fiqh (jurisprudence) from the Qur’aan and Sunnah, and they are mujtahideen in this regard. The mujtahid either gets it right, in which case he will have two rewards, the reward for his ijtihaad and the reward for getting it right, or he will get it wrong, in which case he will be rewarded for his ijtihaad and will be forgiven for his mistake.
Thirdly: the one who is able to derive rulings from the Qur’aan and Sunnah should take from them like those who came before him; it is not right for him to follow blindly (taqleed) when he is believes that the truth lies elsewhere. Rather he should follow that which he believes is the truth. It is permissible for him to follow in matters in which he is unable to come to a conclusion based on the Qur’aan and Sunnah and he needs guidelines concerning a particular issue.
Fourthly: Whoever does not have the ability to derive rulings himself is permitted to follow one whom he feels comfortable following. If he is not comfortable following him then he should ask until he finds someone with whom he is comfortable.
Fifthly: From the above it is clear that we should not follow their opinions in all situations and at all times, because they may make mistakes, but we may follow their views that are sound and are based on the evidence.
Fataawa al-Lajnah, 5/28