Karlo Broussard addresses this question in a Catholic Answers piece. It is quite good. He points out that when scripture uses the word “reckon” in regard to our justification by God’s grace that it can only mean that God affirms what is real in us, namely our intrinsic holiness in grace. The Vulgate Latin usually uses the words reputatam est (reputed, in the Catholic Douay English). To allege, Broussard argues, that God is declaring a man just only outwardly by a justice imputed by faith in Christ and not inwardly is tantamount to saying that God is reckoning something to be so that is not so. Thus, according to Protestant theology, where Saint Paul declares in Romans 4:3, that Abraham believed God, and it was reckoned to him unto justice, this reckoning of justice is not de facto intrinsic justice but a nominal justice imputed unto us by the only Just One, Jesus Christ. In this warped scenario, the heretic must affirm either that scripture is declaring that God is reckoning (reputing) something to be so that is not so or that Saint Paul has deceived his readers with the same false attribution of a non-intrinsic justice.
Catholic Answers: The Council of Trent taught that through baptism believers “are made innocent, immaculate, pure, harmless, and beloved of God.” The Catechism of the Catholic Church concurs: “Justification is not only the remission of sins, but also the sanctification and renewal of the interior man” (1989). Full article is here.