In man two things may be considered: what there is of God, and what there is of man. Of man there is whatever points to defect; but of God is all that makes for salvation and perfection, according to the text: “Destruction is thy own, O Israel; thy help is only in me.” Now humility properly regards the reverence whereby a man is subject to God. And therefore every man ought to count himself, for what there is of his own, inferior to his neighbor for what there is of God in that neighbor. But humility does not require one to count what there is of God in himself inferior to what he can see of God in another. For they who partake of the gifts of God know that they have them, according to the text: “That we may know the things that are given us from God.” And therefore, without prejudice to humility, men may prefer the gifts they have themselves received to the gifts of God that they see bestowed on others, as the Apostle says: “In other generations it was not known as now it is revealed to his holy apostles.” In like manner humility does not require that any man should deem what is his own in himself inferior to that which is of man in his neighbor: otherwise everybody would have to reckon himself a greater sinner than everybody else; whereas the Apostle says, without prejudice to humility: “We by nature are Jews, and not of the Gentiles sinners.” But a man may reckon that there is some good in his neighbor which he has not himself got, or some evil in himself that is not in another man; and on that score he may in humility esteem himself inferior to another. [Summa Theologiae: Question CLXI: Of Humility]