A lot of people know that Muslims will always follow the Quran because they believe that the things that are being said here are true. What some Non-Muslims are not aware of is that there is a slight distinction between two different types of Muslims, namely the Shia and Sunni Muslims. 85% of Muslims are Sunni Muslims, while the remaining 15% are Shia Muslims.
Sunni Muslims believe that the leadership of the religion is not a birthright and should be earned, but the Shia Muslims believe otherwise. They feel that Imam is sinless, and the authority should be passed on to him. Sunni Muslims feel that they can vote on who the next leader should be.