Protestant Christianity is an umbrella term for a broad range of Christian churches and movements that are neither Catholic nor Orthodox, most of which have their origin in the Reformation, a 16th-century western European reaction against Roman Catholicism. Although there are wide variations in structure and doctrine, their beliefs are typically characterized by an emphasis on grace as the means of salvation, scripture as the source of authority, and an expanded role for laity. Having spread from western Europe to all continents, Protestantism is now second only to Catholicism as the dominant strain of Christianity in the world.