14 They which say these things, do not understand that as well each one of the wicked is in that measure for endurance of any ills more hard, in what measure the lust of the world is mightier in him; as also that each one of the just is in that measure for endurance of any ills more brave, in what measure in him the love of God is mightier. But lust of the world has its beginning from choice of the will, its progress from enjoyableness of pleasure, its confirmation from the chain of custom, whereas “the love of God is shed abroad in our hearts,” not verily from ourselves, but “by the Holy Spirit which is given unto us.”
And therefore from Him comes the patience of the just, by Whom is shed abroad their love (of Him). Which love (of charity) the Apostle praising and setting off, among its other good qualities, says, that it “bears all things.” “Charity,” says he, “is magnanimous.” And a little after he says, “endures all things.” The greater then is in saints the charity (or love) of God, the more do they endure all things for Him whom they love, and the greater in sinners the lust of the world, the more do they endure all things for that which they lust after.
And consequently from that same source comes true patience of the righteous, from which there is in them the love of God; and from that same source the false patience of the unrighteous, from which is in them the lust of the world. With regard to which the Apostle John says; “Love not the world, neither the things that be in the world. If any man love the world, the love of the Father is not in him: because all that is in the world, is lust of the flesh, and lust of the eyes, and pride of life; which is not of the Father, but is of the world.” This concupiscence, then, which is not of the Father, but is of the world, in what measure it shall in any man be more vehement and ardent, in that measure becomes each more patient of all troubles and sorrows for that which he lusts after.
Therefore, as we said above, this is not the patience which descends from above, but the patience of the godly is from above, coming down from the Father of lights. And so that is earthly, this heavenly; that animal, this spiritual; that devilish, this Godlike. Because concupiscence, whereof it comes that persons sinning suffer all things stubbornly, is of the world; but charity, whereof comes that persons living aright suffer all things bravely, is of God. And therefore to that false patience it is possible that, without aid of God, the human will may suffice; harder, in proportion as it is more eager of lust, and bearing ills with the more endurance the worse itself becomes: while to this, which is true patience, the human will, unless aided and inflamed from above, does not suffice, for the very reason that the Holy Spirit is the fire thereof; by Whom unless it be kindled to love that impassible Good, it is not able to bear the ill which it suffers.
Source: On Patience (New Advent)