The base of Matahib was Quran and Hadith. Perhaps in past not all the Hadith were known to each Imam that is why they concluded the different rules for same topics. Now so much work on hadith has been performed that we know which hadith is Saheh, Hasan or Zaeef. Now why cannot all the matahib can be converted in one. If it is not possible then tell me that what Matahab will the Imam Mehdi and Hazrat Easa Alleh Salam follows or they going to merge the four Matahib in one.
At the outset, we wish to point out any ruling in the Qur'aan or Hadith
which is Qatiyyus-suboot (expressly proven) and Qatiyyud-Dalaalah (expressly
indicative) cannot be debated. There can be no differences of opinion on
such a matter. All the Fuqahaa are unanimous on that. If there is a ruling
which is either Qatiyyus-Suboot but not Qatiyyud-Dalaalah or vice versa,
then only there will be differences of opinions among the Fuqahaa based on
the juridical ideologies and principles of interpretation.
The same applies with any ruling in a Hadith. The Fuqahaa were oceans of
knowledge. They were experts in Tafsir, Hadith, Ilmul Kalaam, Usul-e-Tafsir,
Usul-e-Hadith (principles of understanding the Qur'aan and principles of
understanding Hadith). They had the ability to deduce rulings not expressly
mentioned in the Qur'aan and Hadith. The differences of opinion among the
Imaams are academic and in their deductions expressed intellectual honesty,
hence, the differences of opinions. Imaam Mahdi and Hadhrat Eesa (Alayhimus
salaam) will be Mujtahids and will also make Ijtihaad when the need arise.
and Allah Ta'ala Knows Best
Mufti Ebrahim Desai