The Sunni and Shia sects started based on a different point of view about who will lead the Islamic state after Prophet Muhammad (pbuh) passed away. Some claimed that Ali, nephew and son in law of Prophet Muhammad should be the next president; another group claimed that the best companion of Prophet Muhammad Abu Bakr should be the next president. So the difference started with a political separation but not with a different belief system. Throughout history there has been also other occasions where these two groups have sided different opinions and interpretations and also some of them moved away from each other and settled in different geographies, which exacerbated the differences.
However the mainstream view is that all Muslims are brothers and sisters. We might have certain different interpretations on some aspects related to religion but we all believe that Muhammad (pbuh) is messenger of God and Quran is a revelation from God, our commonalities outweigh the differences by far and in most parts of the world Sunnis and Shias live and have been living peacefully together, the mosques are open for everyone from any sect to come and pray together. The clashes that you see on the media are not religiously motivated, they are mostly political. We can pray in each other’s mosques. We do not say I am Sunni or Shia we say I am Muslim, when someone asks our religion. 6 Pillars of faith and 5 pillars of Islam are the same between Shia and Sunni Muslims. But there are main 3 differences:
- Prophets grandchildren are innocent. For us not. They believe their Imams are innocent.
- In Sunni Islam, we have authenticated chain of Hadith. They do not have the same chain. Also they do not quote all the Sahabas.
- They do not accept the first 3 Khalifas. (Successors of the Prophet)
- It started as a political disagreement
- We are both Muslims with some differences
Or from different point of view: Sunni – shiah aren’t analogous to the different sects in Christianity. For example, all Muslims all around the World, believe in the absulute oneness of God that God is only one and all the wonderful attributes. But our Christian brothers and sisters have different concept of God. The Jehovah’s Witnesses they don’t believe in the Trinity, but only in sonship of Jesus But our Protestant and Catholic brothers and sisters, they believe in Trinity. So, fort he concept of God, all the Muslims are united.
On the other hand, All the muslims are united in saying that there is only one version of the Quran in Arabic all over the World. But Christian brothers and sisters have different versions of Bible. Like the Protestans have 66 books in their Bible, Catholica has 73, Greek Orthodox have 78 books.