Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother, thank you for your question and for your keenness to be more knowledgeable about Islam and its rulings.
There is no obligation in Islam for any Muslim to follow any Madhhab. Rather, every Muslim should follow the scholar or Madhhab he trusts without criticizing the others about the scholars or Madhhabs they follow. Also, a wife is not obliged to follow her husband’s madhhab.
In response to the question you raised, the European Council for Fatwa and Research (ECFR) issued the following fatwa:
Following a particular School of Fiqh (Mathhab), either the famous four ones or others, is not obligatory from the Shari`ah point of view. Indeed, any matter is not obligatory unless clearly stated by the Qur’an or the Sunnah, and Allah Almighty and His Prophet (peace and blessings be upon him) certainly did not command Muslims to follow a certain Imam or jurist. The only obligation upon each and every Muslim is to follow the Qur’an and the Sunnah that are the only two false-proof sources which do not err nor misguide. Any other source is subject to debate and discussion.
Moreover, the Imams themselves were reported to have advised their students not to imitate them. However, it is agreed that whoever possesses insufficient knowledge, does not have a Madhhab, but rather follows whoever gives him or her Fatwas and knowledge.
Therefore, an individual who has not reached a level of knowledge allowing him or her to evaluate and weigh the evidence of rulings and to compare between them to find the stronger and more solid, does not have a Madhhab. This is because choosing a particular Madhhab implies that one has compared its principles with the principles of others and has come to the decision which it is stronger than others. This can only be done by a scholar who possesses sufficient knowledge to compare between various rulings and principles, whilst all others follow the Madhhab of their scholar.
So, whenever a matter arises which people do not know its ruling, the scholar would tell them what to do according to his knowledge (if he was a scholar) or according to his Madhhab if he was a follower of a particular school. The individual who posed the question must then accept the ruling of this scholar, as Allah Almighty stated in the Qur’an, “If you realize not, ask of those who possess the Message.” (An-Nahl 16:43)
Prophet Muhammad (peace and blessings be upon him) also stated in a Hadith regarding certain people who faced a problem, “Why did they not ask when they failed to know? Indeed the cure of an ignorant person is to ask.” (Abu Dawud)
If a Muslim lives in a country where all the scholars follow a particular Madhhab, then it is permissible for him or her to follow the common Madhhab of the country, as in this case, they would actually be following the Madhhab of their scholars as described above.
However, it is wrong for one to become fanatical about his or her Madhhab and criticize others. One must also desert his or her Madhhab in regards with any particular matter, if it becomes clear that the view of their Madhhab is weaker, in terms of evidence, than that of others regarding the same matter. This is because a Muslim must always follow the stronger evidence.
Imam Abu Hanifa once said, “This is our opinion, but whoever comes with a better opinion, we shall accept that from him”. Imam Malik also stated, “Everyone says true and false apart from he who is lying in this grave (and he pointed to the grave of Prophet Muhammad, (peace and blessingsbe upon him)”. Imam Shafi`i once stated, “If a Hadith proves to be correct, then take it and discard my opinion”.
Each Muslim is free to choose any Madhhab, which they are convinced is more solid, and it is not obligatory for a son to follow his father nor for a wife to follow her husband in this regard.
It is our belief, particularly in regards with new Muslims, that it is much better that they do not follow a particular School of Fiqh, as this would cause them great difficulties, whilst Allah Almighty has decreed Islam a religion of simplicity. It is sufficient that they have been guided to Islam in all its openness and warmth and there is no sense in leading them to the tightness and strictness of a particular Madhhab.
To sum up, a new Muslim is not obliged to follow a particular Madhhab, but if they do so for one reason or another, then a wife is under no obligation to follow her husband’s Madhhab.
Allah Almighty knows best.