Question

What issue divided Shiite and Sunni Muslims?

Answer 1

The issue that divided Shiite and Sunni Muslims was that Sunni wanted a caliph who was a pious community man, and simply a leader not a holy man. Shiites believe that the only true successors are blood-kin to Mohammad, and divinely inspired.

Answer 2

Answer: The issue of choosing a caliph

Explanation: The issue that divided Muslims shortly after Muhammad's death was who will succeed Muhammad, i.e. who will be the caliph. Sunni had the thought that anyone is capable enough and qualified can be religious leader - caliph, so it does not have to be from Muhammad's family. Shiite thought that the caliph could only be Muhammad's cousin, following the principle of royal inheritance.