21. No one is just except by God's illumination, not by comparison.—This verse was spoken above by blessed Job, and now is repeated in his reproach. For every just man is just by God's illumination, not by comparison. For human justice, compared to its Author, is injustice, because even if man had persisted in his very original condition, the creature could not be made equal to the Creator (Job IX, 2). Yet to the heavier burdens of his defect there was added also the fault which the plotting serpent brought in and the weakened woman urged on (Genesis III, 6). Whence now, because man is born through the woman subjected to fault, the infirmity of the first guilt is propagated in the offspring.
And because the branch of the human race rotted in its root, it in no way stands firm in the greenness of its own condition. Whence it is now rightly said: 'Can man be justified compared to God, or he who is born of woman appear clean?' As if it were openly said: Let not man be proud against his Author; let him consider whence he came here, and understand what he is. But behold, some, aided by the gift of the Spirit, are raised up against the infirmity of their flesh, shine forth in virtues, are illustrious even by the miracles of signs; yet there is no one who passes through life without fault, so long as he bears the flesh of corruption. Whence it is further added: