He is thought by some to have been a lawyer but owing to the influence of his mother, famed for her sanctity, he abandoned secular pursuits as a young man and entered the monastery of Lérins.

[2] His career as abbot lasted about twenty or twenty-five years during which he attained a high reputation for his wonderful gifts as an extempore preacher and for his stern asceticism.

This elevation did not make any change in his manner of life; he continued his ascetic practices, and frequently returned to the monastery of Lérins to renew his fervour.

In spite of his activity in the discharge of his duties as bishop, he participated in all the theological discussions of his time and became known as a stern opponent of Arianism in all its forms.

For this, and as is said for his view, stated below, of the corporeity of the human soul, he incurred the enmity of the Arian Euric, King of the Visigoths, who had gained possession of a large portion of Southern Gaul, and was banished from his see.

At the request of the bishops who composed these synods, and especially Leontius of Arles, Faustus wrote the Libri duo de Gratia Dei et humanae mentis libero arbitrio, in which he argued against the doctrines of the predestinarians as well as those of Pelagius.