St. Hilary of Poitiers was a 4th-century bishop who would later be named a doctor of the Church for his profound spiritual and theological writings.
Pope Benedict XVI commented on his life and writings during a general audience in 2007 and said, "To sum up the essentials of his doctrine, I would like to say that Hilary found the starting point for his theological reflection in baptismal faith."
One of St. Hilary's central writings was De Trinitate, which reflected on the Holy Trinity, a central teaching that lays the foundation for baptism.
For St. Hilary, his writings became his prayer, and at the end of De Trinitate, he reflected on his own baptismal faith, as Pope Benedict XVI points out:
Fidelity to God is a gift of his grace. Therefore, St. Hilary asks, at the end of his Treatise on the Trinity, to be able to remain ever faithful to the baptismal faith. It is a feature of this book: reflection is transformed into prayer and prayer returns to reflection. The whole book is a dialogue with God.
Here is the prayer that St. Hilary composed, which we can pray along with him, asking God for grace to be faithful to our baptism.
"Obtain, O Lord...that I may keep ever faithful to what I have professed in the symbol of my regeneration, when I was baptized in the Father, in the Son and in the Holy Spirit. That I may worship you, our Father, and with you, your Son; that I may deserve your Holy Spirit, who proceeds from you through your Only Begotten Son... Amen"