The Concurrence and Unanimity of the People Called Quakers is a book written by Robert Barclay, a Scottish Quaker theologian, in 1677. The book is a defense of the Quaker faith and its practices, particularly the belief in the inner light, or the direct guidance of God within each individual. Barclay argues that the Quaker faith is not a new religion, but rather a return to the original teachings and practices of early Christianity. He also addresses...