From a homily given by St John Paul II for Divine Mercy Sunday, 22 April 2001, § 4-6:
Jesus entrusted to [the fearful, astounded disciples] the gift of “forgiving sins”, a gift that flows from the wounds in his hands, his feet, and especially from his pierced side. From there a wave of mercy is poured out over all humanity.
Let us relive this moment with great spiritual intensity. Today the Lord also shows us his glorious wounds and his heart, an inexhaustible source of light and truth, of love and forgiveness. The Heart of Christ! His “Sacred Heart” has given men everything: redemption, salvation, sanctification. (…)
Through the mystery of this wounded heart, the restorative tide of God’s merciful love continues to spread over the men and women of our time. Here alone can those who long for true and lasting happiness find its secret. “Jesus, I trust in you”. This prayer, dear to so many of the faithful, clearly expresses the attitude with which we too would like to abandon ourselves trustfully into your hands, O Lord, our only Saviour.
You are burning with the desire to be loved, O Jesus, and those in tune with the sentiments of your heart learn how to build the new civilization of love. A simple act of abandonment is enough to overcome the barriers of darkness and sorrow, of doubt and desperation. The rays of your Divine Mercy restore hope, in a special way, to those who feel overwhelmed by the burden of sin.