The Sacred Scripture presents God as infinite mercy, but also as perfect justice.... How can the two be reconciled? They may appear to be contradictory, but this is not the case, as it is precisely God's mercy that leads us to achieve true justice. In the legal administration of justice, we see that those who consider themselves to have been victims of abuse consult a judge in court and ask that justice be done. It is a retributive justice, inflicting punishment on the guilty, according to the principle that each person receives what he deserves. … But this route does not lead to true justice, as in reality it does not conquer evil, it simply limits it. Instead, only by responding with good can evil truly be conquered.
[The Bible, he explained, proposes a different form of justice, in which the victim invites the guilty party to convert, helping him to understand the harm he has done and appealing to his conscience.] In this way, recognising his blame, he can open up to the forgiveness that the injured party offers. This is the way of resolving conflicts within families, in relations between spouses and between parents and children, in which the injured party loves the guilty and does not wish to lose the bond between them. It is certainly a difficult path: it demands that the victim be disposed to forgive and wishes for the salvation and the good of the perpetrator of the damage. But only in this way can justice triumph, as if the guilty party acknowledges the harm he has done and ceases to do so, the evil no longer exists and the unjust becomes just, as he has been forgiven and helped to find the way of good.
--Pope Francis, General Audience, February 3, 2016,
This was taken from a Vatican Information Service report which mixes summary and direct quotes; the sentence in brackets is the former.