Roman Catholics are correct that God's grace increases the cardinal virtue of justice within us. They are wrong, however, to claim that the verb "to justify" in the Bible refers to our being made more and more just.
The verb "dikaioo" (to justify) refers to God's forensic declaration that we are legally righteous before Him based on Christ's imputed righteousness alone.
On the other hand, the noun "justice" or "righteousness" in the Bible can refer either to Christ's righteousness imputed to us, to righteousness (justice) inherent within us, or to both.