Jesus
Allah is the spiritual leader of muslims.
I'm not Muslim but I think their leader is Mohammed.
The Aga Khan is the spiritual leader of the Ismailis.
Caliphs were successors of Muhammad as spiritual and temporary leader of the Muslims. They administered the empire by keeping everyone in line.
Prophet Muhammad (peace be upon him) who was born in 570 AD. God revelation of Quran to prophet Muhammad through the angel Gabriel (Jibril) started in year 610 AD through the year 632 (year pf prophet Muhammad; PBUH; death).
the pharaohs were considered a monach and a spiritual leader.
A spiritual leader is a person who leads people through the beliefs of spirituality.
Nirmal Baba is an Indian spiritual leader.
Muslims do not have one leader, like a pope. There are many many scholars who are well-respected by most Muslims, though.
Yes, Muslims can read the Bible and gain insights from it for their own spiritual growth and understanding.
A kafir can not lead Muslims. Only a Muslim can lead Muslims.
Saladin led the Muslims in some of the Crusades.