Saint Hilary of Poitiers was born to wealthy pagan parents around the year 315. He married early in life and had children, including a daughter, Saint Abra. He received a good education in the classics and studied Neo-Platonist philosophy. After studying the Old and New Testament writings, however, he became a Christian in 353, received the sacrament of baptism along with his wife and his daughter, and soon was elected bishop.
During this time a heresy called Arianism had become widespread. Arianism denied the divinity of Christ, claiming that he had been created by God and was not eternally begotten by the Father, as Christians believed. Saint Hilary was exiled to Phrygia for four years by the Roman emperor, Constantius II, for not condemning Saint Athanasius, the leading opponent of Arianism.
While in Phrygia, Hilary wrote De trinitate (On the Trinity), the first work in Latin to deal with controversies about the Trinity. In De synodis (Concerning the Synods), he explained the history of the Arian controversy and directed the faithful to rally against those who believed in it.
Even after returning to Poitiers, Hilary spent his last years combating Arianism. His constant reaffirmation of Christian orthodoxy, almost alone in Gaul, earned him the title of the Athanasius of the West.
St. Hilary died in the year 367. He was declared a doctor of the church in 1851 by Pope Pius IX, and his feast day is celebrated every year on January 13.