He was the second and youngest surviving son of duke Theodore Eustace, Count Palatine of Sulzbach (1659–1732) with his consort Eleonore Maria Amalia of Hesse-Rotenburg (1675–1720).

His elder brother was Joseph Charles, Count Palatine of Sulzbach.

After the death of his elder brother Joseph Charles, John Christian Joseph became the eventual designated heir of the Electoral Palatine.

Charles III Philip, Elector Palatine, a member of the Palatine Neuburg line of Wittelsbach failed to produce a legitimate male heir, and his brothers also.

By 1716 it was evident that the Neuburg line would become extinct and that the Sulzbach branch would succeed them.