He was born into a patrician family on 25 November 1663 in
Neuchâtel, in the
Principality of Neuchâtel, the son of the Reformed pastor Johann Rudolf Ostervald. He was educated at
Zürich and at
Saumur (where he graduated), studied
theology at
Orléans under
Claude Pajon, at
Paris under
Jean Claude and at
Geneva under
Louis Tronchin (
de), and was ordained to the ministry in his native place in 1683. He spent most of his life at Neuchâtel, first as a deacon, then from 1699 a pastor, and finally he was elected
deacon. Besides this he gave lectures at the academy of theology. As preacher, pastor, lecturer and author, he attained a position of great influence in his day, he and his friends,
J. A. Turretini of Geneva and
S. Werenfels (1657-1740) of
Basel, forming what was once called the Swiss triumvirate. In matters of theology, Ostervald thought to show a leaning towards
Socinianism and embraced
Arminianism, emphasizing the freewill of the man. His innovative proposals embraced dogmatics,
exegesis (his important adaptation of a translation of, and commentary on the
Bible),
liturgy (Bible reading instead of preaching),
hymnology and moral theology (importance of good deeds and moral life). His writings had a great influence, bearing spiritual renewal among
Waldensian,
Dutch,
German,
Hungarian and
Scandinavian Protestants. Moreover, the English Royal Society for the Propagation of the Gospel in Foreign Parts – of which he was a member – brought his teachings to the countries of the
Middle East,
India,
Canada and the
West-Indian Islands. His highly influential oeuvre was later called "the second Reformation". In August 1746 he had a stroke in the pulpit. He died in Neuchâtel on 14 April 1747 after 61 years of service. His pastor's office was inherited by his son Jean Rodolphe (1687-1764). ==Works==