Thank you for giving me the opportunity to read and comment on your blog post, “Do Catholics Believe in Justification by Faith Alone?” Your post is thoughtful and engaging as is usual from you. At the risk of being overly succint, I offer a response in the form of the following points:
1. You mix sanctification and justification. It is vital that they be understood distictly, otherwise no ground is left for assurance of salvation, for “in much we offend all”, even as regenerate Christians. A justification in part based on our own righteous works, (albeit works the Holy Spirit is producing in us) is but a house built upon sand, because we are still sinners.
2. Our good works cannot be the forensic and juridicial basis for our right standing before God, and our full acquittal for having broken his holy law, because they are still quite tainted by sin. By that standard, we would perish, even by the works that the grace of God produces in us. It is not enough to obey somewhat in sin-tainted works. The law requires perfect obedience, not partial obedience.
3. Even if Christian perfection were something that could be attained in this life, as Wesley and some others have (erroneously) taught, this would be entirely insufficient as a basis for a standing of righteousness before God’s law-court. Once one has offended, one doesn’t make up for it by doing good works–even sinless good works. One offense is sufficient to bring condemnation. Furthermore the imputation of Adam’s sin to his posterity imputes sin and its guilt to them, and this is alone sufficient to prevent anyone from being justified by the most sinless, perfect good works (if it were possible for us to do such works.)
4. God promises in Scripture to reward the good works of the saints, not because of some instrinsic worth in them inducing him to be pleased with them, for in every good work we yet have the taint of sin, which is naturally a stink to his nostrils. He has promised to reward them not of merit, but of grace, through the Mediatorial intercession of Jesus Christ, forgiving even the iniquity of our good works and accepting them for the sake of Christ’s own righteousness.
5. It may still be possible for a loyal Roman Catholic to hold to a monergistic soteriology as did the Jansenists, Augustinians and Dominican friars, but this is questionable since the Council of Trent, which adopted a Jesuitical semi-pelagian view that seemed to the then pope to contrast better with the Protestant Reformers. But this is not justification.
6. In answer to your question, as you demonstrate in your post, the Roman Catholic view is justification, not by faith alone, but by faith, hope, and love.
7. An imputed alien righteousness is no more a “legal” fiction than citizenship status conferred to an adopted child, recognized by courts of law. What is external is made internal in time, by the sanctifying power of the Holy Spirit. Justification is a declaratory and forensic declaration of righteousness by imputation.
8. While it’s true that “without holiness shall no man see the Lord”, this is not a part and parcel of justification, but its fruit. It’s not that the justified sinner lacks any legal or forensic right to be accepted in God’s presence–it’s just a matter of practical fitness, since God is holy, and there can be no sin in his presence. Furthermore, it is the goal of his grace to make us holy, so that we will on that day be fit to dwell in his presence. Eph 1:4
9. I recommend that you and others studying justification read carefully the OPC Report on Justification, which makes important distinctions in these topics we’re discussing in response to some new and romanizing teachings on justification in Reformed circles, namely the Federal Vision and the New Perspective on Paul: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwi43_DVltPPAhUBVGMKHXerCwAQFggeMAA&url=https%3A%2F%2Fwww.opc.org%2FGA%2Fjustification.pdf&usg=AFQjCNFkx_ZgNbV-Lm0-J2cj5hffaxULjQ