The author praises Gratian's zeal for instruction in the Faith, and speaks lowly of his own merits. Taught of God Himself, the Emperor stands in no need of human instruction; yet this his devoutness prepares the way to victory. The task appointed to the author is difficult: in the accomplishment whereof he will be guided not so much by reason and argument as by authority, especially that of the Nicene Council.
1. The Queen of the South, as we read in the Book of the Kings, came to hear the wisdom of Solomon. Likewise King Hiram sent to Solomon that he might prove him. So also your sacred Majesty, following these examples of old time, has decreed to hear my confession of faith. But I am no Solomon, that you should wonder at my wisdom, and your Majesty is not the sovereign of a single people; it is the Augustus, ruler of the whole world, that has commanded the setting forth of the Faith in a book, not for your instruction, but for your approval.
2. For why, august Emperor, should your Majesty learn that Faith which, from your earliest childhood, you have ever devoutly and lovingly kept? “Before I formed you in your mother's belly I knew you,” says the Scripture, “and before you came forth out of the womb I sanctified you.” Sanctification, therefore, comes not of tradition, but of inspiration; therefore keep watch over the gifts of God. For that which no man has taught you, God has surely given and inspired.
3. Your sacred Majesty, being about to go forth to war, requires of me a book, expounding the Faith, since your Majesty knows that victories are gained more by faith in the commander, than by valour in the soldiers. For Abraham led into battle three hundred and eighteen men, and brought home the spoils of countless foes; and having, by the power of that which was the sign of our Lord's Cross and Name, overcome the might of five kings and conquering hosts, he both avenged his neighbour and gained victory and the ransom of his brother's son. So also Joshua the son of Nun, when he could not prevail against the enemy with the might of all his army, overcame by sound of seven sacred trumpets, in the place where he saw and knew the Captain of the heavenly host. For victory, then, your Majesty makes ready, being Christ's loyal servant and defender of the Faith, which you would have me set forth in writing.
4. Truly, I would rather take upon me the duty of exhortation to keep the Faith, than that of disputing thereon; for the former means devout confession, whereas the latter is liable to rash presumption. Howbeit, forasmuch as your Majesty has no need of exhortation, while I may not pray to be excused from the duty of loyalty, I will take in hand a bold enterprise, yet modestly withal, not so much reasoning and disputing concerning the Faith as gathering together a multitude of witness.
5. Of the Acts of Councils, I shall let that one be my chief guide which three hundred and eighteen priests, appointed, as it were, after the judgment of Abraham, made (so to speak) a trophy raised to proclaim their victory over the infidel throughout the world, prevailing by that courage of the Faith, wherein all agreed. Verily, as it seems to me, one may herein see the hand of God, forasmuch as the same number is our authority in the Councils of the Faith, and an example of loyalty in the records of old.
Source: On the Christian Faith (De fide) (New Advent)