St. Hilary (315-368)
The son of a pagan noble, Hilary embraced the faith after rigourously studying the Bible. He was made the Bishop of Poitiers, but he was later exiled for opposing the emperor's attempt to run the Church. He wrote great works explaining the faith, and is now a Doctor of the Church.

Reflections from the Saints

To those who wish to stand in God's grace, neither the guardianship of saints nor the defenses of angels are wanting.
– St. Hilary