Catholic Catechism:
1991 Justification is at the same time the acceptance
of God's righteousness through faith in Jesus Christ. Righteousness
(or "justice") here means the rectitude of divine love. With
justification, faith, hope, and charity are poured into our hearts,
and obedience to the divine will is granted us.
2019 Justification includes the remission of sins, sanctification,
and the renewal of the inner man.
2018 Like conversion, justification has two aspects. Moved by
grace, man turns toward God and away from sin, and so accepts
forgiveness and righteousness from on high.
Council of Trent’s teaching:
Canon IX  If any one says, that by faith alone
the impious is justified; in such wise as to mean, that nothing else
is required to co-operate in order to the obtaining the grace of
Justification, and that it is not in any way necessary, that he be
prepared and disposed by the movement of his own will; let him
be anathema.