All men used to be a single ‘Ummah (i.e. on a single faith). Then (after they differed in matters of faith), Allah sent prophets carrying good news and warning, and sent down with them the Book with Truth to judge between people in matters of their dispute. But it was no other than those to whom it (the Book) was given who, led by envy against each other, disputed it after the clear signs had come to them. Then Allah, by His will, guided those who believed to the truth over which they disputed; and Allah guides whom He wills to the straight path.