From Moralia in Job, Book 28 (ca. 595)

A man may now believe eternal truths, but he fears them not; he boldly involves himself in sins of the flesh and of the spirit. But when the fear of future things is suddenly infused into him, in order that the edifice of a good life may rise up, the foundations are now erected. When the foundation then of a wholesome dread has been laid, and the fabric of virtue is being raised on high, it is necessary for everyone to measure his strength, as he is making progress. So that though he has already begun to be great by the divine building, he may without ceasing look back to what he was; in order that humbly remembering what he was found in merit, he may not arrogate to himself what he has been made by grace.

Whence also blessed Job is now brought back to himself by the voice from above, and, that he may not dare to boast of his virtues, he is reminded of his past life. And it is said to him, “Where were you when I was laying the foundations of the earth?” As if the Truth openly said to the justified sinner, “attribute not to yourself the virtues which were received from me. Exalt not yourself against me by reason of my own gift. Call to mind where I found you, when I laid the first foundations of virtue in you, in my fear. Call to mind where I found you, when I confirmed you in my fear. In order then that I may not destroy in you that which I have built up, you must not cease to consider with yourself, what I found you.”

For whom has the Truth not found either in sins or excesses? But after this we can well preserve that which we are, if we never neglect to consider what we were. But pride is yet sometimes wont to steal secretly even into careful hearts, so that the thought of good deeds, though slight and feeble, as it advances to a great height of virtue, forgets its own infirmity, and does not recall to mind what it was in sins.

Whence also Almighty God, because he sees that our weakness is increased even by salutary remedies, places limits to our very progress, that we may have some excellencies of virtues, which we have never sought for, and that we may seek after others, and yet be unable to possess them. In order that our mind, when unable to attain these things which it desires, may understand that it possesses not of itself those even which it does possess, and that, from those which are present, those which are wanting may be thought of, and that, by means of those that are profitably wanting, those goods that are present may be humbly preserved.

St. Gregory the Great (ca. 540-604) served as Bishop of Rome from 586-604, during a series of invasions and political turmoils. He was a skilled administrator and diplomat, as well as a gifted preacher and writer on the spiritual life. The Moralia in Job, an immense commentary on the Old Testament book is his most important work, written while he was serving as an ambassador in Constantinople before becoming pope. His feast is celebrated on March 12.