Sunni Shia Brotherhood

Muslims should realize that the divide between Sunni and Shia is purely a political disagreement over who would succeed the Prophet Muhammad(pbh) as the leader of the Muslim community. It was not a fundamental rift in religious ideology. Sunnis believe that he did not designate a successor and left it to the community to decide; while Shia believed that Ali, the cousin and son-in-law of the Prophet, was chosen by the Prophet to succeed him. Initially, though, there weren’t any doctrinal differences. Over time, this split developed and eventually there arose some points of religious disagreement. But Shia brothers should realise that the first 3 Qulafa did not cause any harm to the cause of Islam, for e.g Abubakar (ra) was so steadfast in preserving one of the pillars viz. Zakath, that he was prepared to wage jihad as he famously said to his detractors, "even the whole so called Muslims stand against me, I will not budge an iota and will not allow to demolish the pillar of Zakath" and it is a historical fact that all the 4 Qualfa Rashidoon exemplified by their simple & pious life. The character of a person is best manifested by his honesty, simplicity and fear of Allah. They never amassed public wealth and were not behind hunger of fame, leadership, grandeur or false pride. They stood for justice and strived to estabilish rule of Shariah according to the tenets of Islam.
Islam vehemently forbids monarchy as the basic concept of Islamic rule and in no way it is hereditary, the rule of Islam is Democracy, the will of people prevails provided it does not conflict with the Islamic tenets. Islam advocates equitable distribution of wealth generated from Natural resources, as it is Allah's gift to humanity and it does not belong to any coterie. These were strictly adhered by 4 Qulafa Rashidoon. In the later years Omar bin Abdul Aziz (ra) also revived the practice of true Islamic rule.
Today the need of the time is to reestablish the rule of Islam according to the concept of Imam and in this contest Abubaker(ra), Omar(ra),Osman(ra) & Ali(ra) are the earlier Imams who spent their lives for the cause of Islam. Except Abubakar(ra), all were assasinated because of conspiracies hatched by enemies of Islam, however it is tragic that disunity errupted due to Sunni Shia and it is real irony as both Sunni Shia will be answerable to Allah & will be held responsible for breaking the unity of Ummah, which is a very grave sin in Shariah. Even if they pray and perform all the required Ibadah and then they indulge in infighting in the name of Sunni Shia, no doubt all their ibadah will go waste as Unity is fundamental to Islamic way of life.
Before turning to the more external obstacles in the path of the realization of unity, it is important to make clear that unity in the Islamic context does not mean uniformity. If God had wished to create a single nation or people , He would have done so, whereas the Qur’an asserts clearly, "O mankind! Lo! We have created you male and female, and have made you nations and tribes that ye may know one another." (Qur’an; xlix, 13). Unity on the human level means integration of diverse elements, whether they be the male and the female, various ethnic groups, tribes or social classes into a whole by means of a higher principle in the same way that inwardly unity does not mean the destruction of the various tendencies of the soul or thoughts in the mind, but their integration which bestows wholeness upon the human being.