Is the Quran enough?

It is abundantly clear that even Islamic scholars are not enough for clarification of Islamic beliefs. There were some people who believed that the Quran was sufficient for the Muslims after the Holy Prophet's (s.a.w.s.) demise. But can we (always) use the Quran to differentiate between the beliefs of different Islamic sects? The belief of various sects is vastly different and Quran enlightens about itself thus: 'If this was not from the side of God, then there would be contradictions in it.' The uniqueness of the Quran lies in the fact that its meaning do not have any contradictions. However, people have been unable to understand the interpretation of Quranic verses completely. When Hazrat Ali (a.s.) sent Ibne Abbas for talks with the 'Khwarij' (Khwarji are those people who separated from Ali (a.s.) after the battle of Siffin and fought against him in the Battle of Nahawan), he said, 'do not bring forth for them arguments from Quran. Quran carries various facts. You will say something and they will say something else (i.e. you will present some verses and they will present other verses) (Nahjul Balagha. letter no. 77)

This means that Quran alone is not sufficient to end discord between Muslims. If Quran was sufficient there would never had been disagreement between Muslims, because every Muslim believes in Quran and even recites its regularly.