Islam
Islam the religion, Muslims the people. Their principle prophet is Muhammad, who is explicitly not recognised in Christianity. Differs also from Christianity in that there is no Trinity and Jesus is considered a prophet rather than the Son of God. The origins of Islam are mysterious but could be considered as the form of religion adopted by the people cast out of Jerusalem by the Romans. Differing from Christians who while sharing much the same religious background are explicitly Roman-derived. Early Christian history includes Arians who seem to have existed in every part of the world where Muslims are today and to have shared the strictly monotheistic approach. It is possible therefore that the difference between Arians then and Muslims today is simply a labelling error. Arguably the result of Trinitarian Christian persecution of Arians in areas where today Muslims predominate could the the precursor the prophesy of Mohammed.