According to the Quran, All the Messengers of God and all of their followers should be one Ummah or one nation in spite of the different times and different places and different languages, because they have the same religion of submission to God and peace on the earth. This is what should be, but what usually happens is something else. The followers of the prophets usually become different sects not one nation. The Quran explains this in chapter of [the Prophets 21:92-93] and chapter of [the Believers: 23:51-52].
This is exactly what happened in Muslim history after the death of the prophet Muhammad. His followers established the early Muslim Empire and plundered the wealth of occupied lands, and then they disputed about this wealth and fought each other in the great civil war. Then each political party tried to justify its situation by false religious excuses, so the political parties have changed to be religious sects.
Muslims now are not one nation but they are three main sects, Sunni, Shiites and Sufi. These sects are further divided in to various sub-sects. Every sect has its own tradition, scholars and scriptures. Sometimes, they accuse each other and excommunicate each other. The Salafi Wahhabi Sunni people are against the Sufi and the Shiites together. There is a long history of enmity among the Sunni and the Shiites. So the talk about the one Muslim nation or Ummah is just a big lie to deceive the masses. Moreover, They have no right to talk in behalf of all Muslims while they are tarnishing the name of Islam for their own ego and favor.
The Ummah is Lost—- Do we need a Messenger???