28 Although he was held in great favor and esteem by Popes, princes and peoples, he was not puffed up, he did not grasp at the slippery and empty glory of men, but ever shone with that Christian humility which "acquires other virtues . . . having acquired them, keeps them . . . keeping them, perfects them"; so that "without it the others do not even seem to be virtues." Wherefore "proffered honor did not even seem to be virtues." Wherefore "proffered honor did not tempt his soul, nor did he set his foot on the downward path of world glory; and the tiara and ring delighted him no more than the lecture platform and garden hoe." And while he undertook so often such great labors for the glory of God and the benefit of the Christian name, he was wont to call himself "the useless servant of the servants of God," "a vile worm," "a barren tree," "a sinner, ashes. . ." This Christian humility, together with the other virtues, he nourished by diligent contemplation of heavenly things, and by fervent prayer to God, by which he called down grace from on high on the labors undertaken by himself and his followers.
Source: Doctor Mellifluus (Vatican.va)