Quakerism rose in England in the 1640s and 1650s searching for a faith that would be, in the words of an early leader, "Primitive Christianity Revived." Quaker was originally a derogatory nickname that Friends came to embrace. Friends emphasized the universality of the Inward Light of Christ and obedience to its leadings that "Jesus Christ has come Himself to teach His people." Quakerism spread to North America in the 1650s. In the eighteenth and nineteenth centuries, Friends became leaders in humanitarian and reform causes, especially antislavery, American Indian rights, women's rights, peace, and humane treatment of the mentally ill. After 1870 missionaries spread Quakerism to Africa, Latin America and Asia. Today, theological diversity characterizes Friends. Some are strongly evangelical, others liberal. Worship styles range from unprogrammed silence to impassioned pastoral preaching.