The Roman Catholic understanding of justification as the sinner's renewal through the reception of created and uncreated grace is essentially flawed because of its ontological assumptions. In absorbing Platonism and other ancient philosophical systems (notably that of Aristotle after the 12th century), Catholicism assumes that righteousness is in fact a quality. It is a quality that you can more of or less of- it is, rather like color. The basic assumption of the Roman Catholic view is that God (who possesses this quality of righteousness archetypally) cannot in fact recognize humans as righteous without said quality becoming a predicate of their being (just as one cannot recognize a wall as blue unless it is in fact painted blue!). Being the embodiment of this quality, he cannot pretend that a certain quality that is not there is in fact there. God is willing to give this quality by his grace, but he must actually see it to count the person as righteous. Hence they find the Lutheran view inexplicable.
What is implicit in the RC understanding of righteousness as a quality is a centered concept of being-which they of course also get from Greek metaphysics. An entity is what is it is because of the qualities that make up its centered essence internal to it. Losing those qualities, the entity loses its essence. There is no sense (as in the Biblical tradition) that righteousness is a judgment of God, more properly, a right relationship with the God.
This scriptural concept of righteousness is true both of God and his relationship to creation. Internally, God is righteous because he is true to his own love and holiness as lived out relationally within the Trinitarian life. Externally, insofar as he enters into covenantal relationship with his creatures, God is righteous because what he does what he says he will do to them and for them (that is, he condemns with the law and redeems with the gospel!).
Because righteousness is not a quality, but a relationship, such a concept implies an ecstatic rather than centered concept of being. Entities are what they are because of something outside of themselves. The Father is the Father because he has the Son, and the Son is the Son because he has a Father. Man is man because of woman- and the creature lives external to itself through God's constant speaking of his existence into being.
Therefore, when it comes to sin and righteousness, the creature is defined by what is external to the center of his or her being. This is exemplified in Paul's discussion of Adam and Christ in Romans 5 and 1 Corinthians 15. Adam is the person of every human person coram Deo. Every person lives through Adam and his rejection of God's grace in favor of his ambitio divnitatis, and therefore all are subject to habitual sin and inevitable death. In the same manner, all are in Christ and therefore suffer the judgment of their old person in him and are righteously resurrected him as well. Coram Deo, Christ is the reality of every person and therefore a new Adam. He defines humans before God and therefore righteousness is not something internal to humans, but something outside of them in Christ: "Though your body be dead, your life is hidden in God in Christ" (Col. 2).
With this, therefore, we observe the basic ontic flaw in the logic of those who rejection of objective justification. Objective justification assumes that Christ is the real reality of humanity before God. Our justification is not therefore a legal fiction because righteousness is not a predicate of our being, but something that exists outside of ourselves already actualized in Christ. This is true irrespective of our faith. What those reject objective justification assume is that being righteous means possessing a certain quality in our being. The predicate "righteousness" cannot be recognized coram Deo unless faith is first present. If faith is present, God can now predicate the quality of righteousness present in Christ to person who has now accepted and received this predicate into their being- though of course in this case by imputation rather than by renewal (as in RC theology). In other words, the two centered realities of Christ and the believer now converge being of the bridge of faith, which prompts God's imputation. In this theology, I am an individual, centered entity, existing on my own. Likewise, so is Christ. The only thing that connects the various qualities present in our beings is faith which prompts God's imputation.
This criticism of the anti-OJ forces use of the concept of faith is of course not meant to say that having faith is not necessary to enjoy the benefits of Christ. Faith does unite the sinner with Christ and bring about salvation through subjective justification. The point is rather that the subjective justification brought about by faith is not a legal fiction or the convergence of two centered entities by an arbitrary judgment of God. Rather, since Christ is the being of my being, having faith means to cease to be self-alienated from my true self which is to be found in the person of Christ. The essence of sin is the be (as Augustine says) curved in on one's self. One's true being is external to one's self in God's address. Adam was "very good" because God continuously gave him the good by his sustaining Word and he passively received it. We now passively receive the good every moment of every day and yet we are not good because he do not praise God and therefore reject his grace in creation. In the same way, the person of my person is Christ and yet if I remain unbelieving, I am alienated from my true reality before God in Christ. I am rejecting God's grace in creation and redemption, and consequently I will be judged. Faith therefore simply means coming to my true self as God has actualized in a new narrative of creation in Christ.