... Because of Shirk, innovations and leaving the Sunnah
All Praise is for Allah (subhaanahu wa ta'aala) Lord of all the creation and May His peace and Blessings be upon is last Prophet Muhammad (sal-Allaahu 'alayhe wa sallam) and upon the Prophet's (sal-Allaahu 'alayhe wa sallam) family and upon the companions and on all those who follow the path of guidance until the last day.
Without doubt the Muslim Ummah is in a divided and fragmented state and that this division is prohibited in Islam. Rather Allah (subhaanahu wa ta'aala) has enjoined upon us to hold onto the rope of Allah (subhaanahu wa ta'aala), which we established is the Qur'an and the Sunnah as understood by the Companions. But how did we reach this state in the first place, what causes disunity?