The Catholic Encyclopedia on Sanctifying Grace
On faith:
If the question be put: In how many truths as a means… must one believe to be saved? many catechists answer Six things: God’s existence; an eternal reward; the Trinity; the Incarnation; the immortality of the soul; the necessity of Grace.”
It seems to me that some of these, like existence of God, immortality of the soul, and even perhaps the necessity of grace, are known by reason; some, like the Trinity, by faith united with reason; and others, like an eternal reward and the Incarnation, by faith alone.
On justification:
The Catholic idea maintains that the formal cause of justification does not consist in an exterior imputation of the justice of Christ, but in a real, interior sanctification effected by grace, which abounds in the soul and makes it permanently holy before God… Although the sinner is justified by the justice of Christ, inasmuch as the Redeemer has merited for him the grace of justification…, nevertheless he is formally justified and made holy by his own personal justice and holiness…, just as a philosopher by his own inherent learning becomes a scholar, not, however, by any exterior imputation of the wisdom of God. … For since sin and grace are diametrically opposed to each other, the mere advent of grace is sufficient to drive sin away; and thus grace, in its positive operations, immediately brings about holiness, kinship of God, and a renovation of spirit, etc. From this it follows that in the present process of justification, the remission of sin, both original and mortal, is linked to the infusion of sanctifying grace as a conditio sine qua non, and therefore a remission of sin without a simultaneous interior sanctification is theologically impossible.”
So, then, sins cannot be forgiven to a bad person? Hmm… Why not say that what is taken away is not sin or sinful habits but guilt for previous sins and the debt of punishment? Then again, as I argued before, even feeling guilt is a response to actual grace.
On participation in the divine nature:
To the difficult question: Of which special attribute of God does this participation [in the divine nature through sanctifying grace] partake? Theologians can answer only by conjectures. Manifestly only the communicable attributes can at all be considered in the matter, wherefore Gonet… was clearly wrong when he said that the attribute of participation was the aseitas, absolutely the most incommunicable of all the Divine attributes.
Aseity is an attribute derivative from simplicity, insofar as God’s essence is existence. But charity is a unitive force. Hence a person in the state of sanctifying grace is “simpler,” more one than an unbeliever. “Be shrewd as serpents and simple as doves.” (Mt 10:16) I think the word “simple” in this phrase refers not so much to innocence but precisely to the simplicity and integrity of the soul acquired as a result of grace. Or maybe to both, as innocence brings peace and self-control and self-contentment which are also the fruits of charity, etc.
On the 7 gifts of the Holy Spirit:
we may possibly assume that God gives in the process of justification also the seven gifts of the Holy Ghost.
I can testify that this assumption is incorrect. A gift of the Holy Spirit is like a flower on a plant. However it is produced, it is something beyond any other grace. It’s extremely rare and just as beautiful. For example, the gift of wisdom is a voice at the very top of your head, a voice of a child, judging generously every good thing good and happy and every bad thing appropriately bad. The sense of personal identity, of selfhood is tremendously sharpened. (When I asked a priest in New York whether he was familiar with this phenomenon, he said he was.)
On the characteristics of sanctifying grace:
Uncertainty:
The heretical doctrine of the Reformers, that man by a fiduciary faith knows with absolute certainty that he is justified, received the attention of the Council of Trent…, in one entire chapter…, three canons… condemning the necessity, the alleged power, and the function of fiduciary faith. The object of the Church in defining the dogma was not to shatter the trust in God… in the matter of personal salvation, but to repel the misleading assumptions of an unwarranted certainty of salvation… In doing this the Church is altogether obedient to the instruction of Holy Writ, for, since Scripture declares that we must work out our salvation “with fear and trembling,” it is impossible to regard our individual salvation as something fixed and certain.
It’s true that Jesus forgives all sins but only to those who want them forgiven. If you are shameless in evil, you are pretty much out of luck.
Inequality:
If man, as the Protestant theory of justification teaches, is justified by faith alone, by the external justice of Christ, or God, the conclusion which Martin Luther… drew must follow, namely that “we are all equal to Mary the Mother of God and just as holy as she”.
If true, then Protestants have made a crucial error: what is equal is not our holiness but our right to forgiveness of sins.
Amissibility:
On account of the grave moral dangers which lurked in the assertion that outside of unbelief there can be no serious sin destructive of Divine grace in the soul, the Council of Trent was obliged to condemn… both these views.
Come on, Protestants, you can’t be serious!
I heartily recommend this whole article for its remarkably modern style and Scholastic precision.