Jesus I trust in you.
The Divine Mercy is not 'cheap grace' by any means. Rather, I'm convinced it is like the Father, running to meet the prodigal son, while he is still at a distance. It is the Father ready to embrace the erring son even before he proclaims his sorrow, even before he is able to blurt out his confession of sin, and even before he is able to ask for mercy. The Father anticipates his return in and through the holy wounds of his dearly beloved Son.
The mercy of God is just.
Jesus Christ crucified is the justice of God ... He is our reconciliation with the Father.
When he appeared to the disciples on the evening of the first day of the week, he did not rebuke them for abandoning him, neither did he shame them for their betrayal or their retreat into hiding. The first thing he said, the very first thing he did, was to grant them peace: "Peace be with you." One Word the father spoke ... St. Teresa of Avila said that "His words are deeds."
Pardon and peace...
Mercy and truth have embraced,
Justice and peace have kissed. Ps. 85
That happens in the sacrament of penance - the tribunal of mercy - at the moment of absolution, pardon and peace embrace the penitent... mercy and love flood the soul.
Mercy - divine love moved by the truth of our misery - pardons ... Divine Justice bestows peace.
It seems to me that it is true to say that these Divine attributes meet in the Divine Mercy. Mercy and Justice. Pardon and Peace. I might be wrong.
UPDATE: "God's justice is his mercy," said Pope Francis as he proclaimed the Jubilee Year of Mercy, which will begin on Dec. 8. - Fr. James Martin, SJ