The following is an old journal entry of mine I was reminded of recently. I think it might have some use to others.
One often missed point in ecumenical discussions is that Catholics view salvation very, very differently.
In Catholic theology, if a person dies in friendship with God then they go to heaven. "Justification" refers to the grace which allows a human being this friendship. In other words, the sacrifice of Jesus nullifies the fall. This grace is received primarily through the sacraments, although it can received otherwise as well. Baptism clears away all of the inner consequences of the fall.
Many non-Catholics would have us believe that a person is saved once and guaranteed that salvation. This would imply that a person who has accepted Christ could rape, murder and commit every kind of abominable sin and still go to heaven if he or she had accepted Christ previously.
To be fair on that aspect, many Protestants will then say of such a person that such actions would indicate that they never were saved in the first place.
How then, can ANYONE assume salvation? I'm certain you have heard of cases where pastors and other spiritual leaders were found to be terrible sinners. If they are not saved, what does that say for the rest of us ordinary people?
This brings back again to a problem of semantics, notably "grace", “justification" and how Catholics view them in the context of salvation. When Catholics use these words they are referring to purification.
To quote David P. Lang's Why Matter Matters:
According to [Luther], the sacraments of Baptism and Penance do not really produce an interior change in the soul. They are merely occasions for God to declare the person "righteous"—an external (or "legal") imputation of justice only, demanding simply a subjective (or "fiducial") trusting faith in Christ the Savior. In actuality (i.e. "ontologically") the soul remains mired in its unregenerate state of corruption; God just covers over the fetid swamp with a white celestial canvas and some heavy supernatural deodorant (as it were). By contrast, the orthodox Catholic position is that sanctifying grace works a profound transformation within the soul, elevating it to a divinized condition consequent upon the removal of sin's stain. (33)
Since Catholics view salvation as genuine purification whereby the soul is made suitable for heaven, repentance of all sin throughout life (and after death in Purgatory) is considered necessary. Of course, this needs to be differentiated from meriting heaven by works-- a soul achieves heaven not by its own power, but through this sanctifying grace of God, which brings us in union with him through the merciful forgiveness of sin. To put it more simply, a person who dies in the grace and friendship of God achieves acceptance into heaven. There is no other work than to simply love God, despise that which offends Him, and seek reconciliation for weakness or error. All the sacraments are thus intended throughout life to bring the individual soul closer to God through grace, combating the evil of the world.
So then, a Catholic is not simply saved. A Catholic is saved through baptism and continually being saved though participation in the grace through the other sacraments of reconciliation and communion. If you ask for an assurance of salvation, a Catholic might answer that he or she is in a state of grace and is saved at the moment were death to occur. While this may seem less than the guarantee given by the Protestants, it is truly more so—Catholics know when they are saved because they can be truly free of the guilt of sin.