Born in La Mure d'Isère in southeastern France, Peter Julian's faith journey drew him from being a priest in the Diocese of Grenoble (1834) to joining the Marists (1839) to founding the Congregation of the Blessed Sacrament (1856).

In addition to those changes, Peter Julian coped with poverty, his father's initial opposition to Peter's vocation, serious illness, a Jansenistic striving for inner perfection and the difficulties of getting diocesan and later papal approval for his new religious community.

His years as a Marist, including service as a provincial leader, saw the deepening of his eucharistic devotion, especially through his preaching of Forty Hours in many parishes.