The Dominican Father Thomas Pegues discusses St. Thomas Aquinas’ Treatise on the Theological Virtues (Summa Theologica II-II, 1-46), wherein he teaches that the most important virtues are the theological virtues: faith, hope, and charity. They are the most important because “they are those whereby man attains his final end as far as he can and ought to attain it in this life so as to merit the possession of his final end in heaven.” Moreover, it is “impossible for man to perform any supernaturally good act without the theological virtues.”
“Faith,” writes Father Pegues, “is a supernatural virtue which makes our mind, even though it understand not, adhere most firmly and without fear of deception to what God has revealed principally about Himself, and of His will to give Himself to us some day as the object of our perfect happiness.” By having faith, one relies “on the authority of God who can neither deceive nor be deceived.” God can neither deceive nor be deceived “because He is Truth itself.”
We know of these truths “through them to whom He has revealed these truths, and through them to whose care He has confided the deposit of His revelation.” God revealed these truths “to Adam to whom He manifested Himself directly; subsequently to the Prophets of the Old Testament; and lastly, to the Apostles at the time of Jesus Christ.”
The written record of divine revelation is found in Sacred Scripture, the Bible. “God is the principal author of these books. . . . He chose certain men, as so many instruments, to write them.” Yet, it is possible for us to misunderstand the sense of Sacred Scripture because parts of it are obscure. “This obscurity is due first of all to the mysteries contained therein, since the Bible treats essentially of truths that God Himself alone knows, such as are beyond the reach of every created mind; this obscurity also arises from the antiquity of these books, which were written primarily for people whose tongue was other than ours and whose lives and customs differed from ours; and, lastly, this obscurity arises from mistakes that have crept either into the copies of the original language, or into the translations made thereof and into the copies of these translations.”
Quotations from Thomas Pegues, Catechism of the “Summa Theologica” of Saint Thomas Aquinas, trans. Aelred Whitacre (New York: Benziger, 1922).