Arnd, Or Arndt, Johann, a German theologian, born at Ballenstedt, Anhalt, Dec. 27, 1555, died at Celle, May 11, 1621. He was pastor successively at Paderborn and Quedlinburg, and in 1599 was appointed preacher to the court at Brunswick. In 1611 he was presented by the duke of Luneburg to the church at Celle, and he soon afterward became superintendent of all the churches of the duchy, which office he held till his death. His writings are marked by great fervor of devotion. His principal work, on "True Christianity," which has been translated into almost all European languages, approaches so near to mysticism that it was attacked during the lifetime of its author as a dangerous and heretical production. The fact that he gave liberally to the poor, while himself in poverty, gave rise to a belief that he had discovered the secret of making gold.