He served as a bishop of the newly created Diocese of Christianssand from 1682 until his death in 1694.
[1] Jacob Jensen Jersin was born in 1633 in Ribe, Denmark and he was baptized in church on 5 July of the same year.
He was the son of Jens Dinesen Jersin [Wikidata] (the Bishop of the Diocese of Ribe) and his third wife.
She was the daughter of Hans Borchardsen [Wikidata], the Bishop of the Diocese of Ribe.
By 1684, however, the bishop finally relented and they moved the episcopal seat to the new Christianssand Cathedral.