St. Augustine and Merely Forensic Justification

It does not appear that St. Augustine’s conception of justification is merely forensic. In Book III of On Free Choice of the Will, he writes:

If…we should see the noble man changed so as to be fit for a heavenly dwelling and then raised to the stars, we would rejoice. But if we should see the depraved criminal, either before or after punishment, raised to a seat of honor in heaven even though he is still as evil as ever, who would not be indignant?

…Unlike the just man…the wicked man, as long as he is wicked, cannot reach the immortality of saints, that is, sublime and angelic immortality…[Book III, chapter IX (pp. 109-110)]

Mere forensic justification does not make the sinner just or holy, as even the Protestant concedes; the claim is that on the basis of what amounts to a legal fiction the sinner is declared “not guilty,” despite the fact that he is still actually a sinner. But St. Augustine here appears to agree with Psalm 14: Such a man isn’t fit for a heavenly dwelling.