Mankind was on one religion; so Allah sent Prophets giving glad tidings and warnings - and with them sent down the true Book to judge between mankind on their differences; and only those to whom it was given created disputes regarding the Book, after clear commands had come to them, due to hostility of one another; so Allah, by His command, made the truth clear to the believers, concerning their disputes; and Allah may guide whomever He wills to the Straight Path.