Is it me or this seems so similar to the Caste System of ancient India (though still prevalent) with distinction based on Ideology instead of social structure..
Shia –Sunni divide is not similar to the caste system but more like a divide between Korus and Pandas of the Mahabharata.
Historically it dates back to the rivalry between the two sons of the leader of Quraish called Abd Munaf. Our holy Prophet was great grandson of Hashim. Whereas his chief rival Abu Sufyian was a descendant of Abdul Shams another son of Abd Munaf.
Shias’ consider Hazrat Ali (RA) who was from Banu Hashim as the rightful heir of the Prophet (PBUH). Banu Ommaya gained resurgence during the reign of Hazrat Osman (RA) and were strong enough to militarily change Hazrat Ali (RA) under the leadership of Muwviya son of Abu Sufiyan. It culminated at Karbala when forces loyal to Yazid, grandson of Abu Sufiyan massacred Hazrat Imam Husain (RA) grandson of the holy Prophet (PBUH) and his small part of followers.
Enmity between the two families ran so deep that Hazrat Ali (RA) one of the Rashideen was publically cursed after every Friday prayers until stopped by a pious Omayyad Caliph Hazrat Omer bin Abdul Aziz.
The difference was originally purely political; theological split occurred 80 years later when descendants of Abbas (Prophet’s uncle and a Hashemite) eliminated the whole Omayyad by killing of nearly 80 princes of the Omayyad branch. However Abbasids were the main reason why Sunni Islam in its various sub sects constitutes 80% of all Muslims.
Split between Shia and Sunnis in Pakistan was not deep when I was growing up and not all Sunnis consider Shias ‘Kaffir’. I am from Sargodha where Sunnis used to set up Sabeel (free water fountains) for the Moharram processions. In Multan family of Yusuf Raza Giyani (current PM) despite being a Sunni used to accompany Tazia procession during Moharram. However large influx of the Deobandis after the partition and especially after Salaafin and Takfiris gained political backing during the bigot Zia era changed the situation.
Shias are also not innocent as some of them curse first 3 Caliphs of Islam, a practice started by the Fatimid Caliphs whose followers are now call Isamilies.
I am not scholarly enough to pass judgement as to what is right. I am dead gainst cursing the any of the Sehaaba especially the Rashideen. At the same time I am staunchly anti Takifiri as I believe that these peoples follow the scholars who were sympathetic to Banu Omayya and were anti Hazrat Ali (RA).
This view has come about when I came across a mosque named ‘Masjid Abu Sufiyan’. Pray tell me when there are scores of very exalted companions names available such as Omar, Osman, Abu Bark, Salman Farsi, Abu Zarr, Ammar Yasser, Amir Hamza, Saad bin Abi Waqas, Zubair etc., must you chose Abu Sufiyan as your place of worship? Doesn’t this indicate a preference of Banu Omayyad above the family of the holy Prophet?
By the way, majority of the religious parties currently under the ‘Difae Pakistan’ are those which are strongly sectarian and anti-Shia.