Catholicism teaches that justification is an ongoing process that depends on the degree of real, personal righteousness we achieve. According to Rome, Christ’s merit imputed to us is not enough to save; we must earn more merit of our own through the sacraments and other good works. Righteousness is infused into us (rather than being imputed to us). But it is obvious that we are not perfectly righteous by any practical measure. So the righteousness we obtain by grace must be perfected by our own efforts.