VATICAN CITY, DEC. 4, 2002 (Zenit.org).- The joy of experiencing God's forgiveness makes the believer his witness in the world, says John Paul II.

Commenting on verses 12-16 of the famous Psalm 50(51) -- the Miserere ("Have mercy on me") -- the Pope described the joy that can only be experienced when one realizes the gravity of his sin and the greatness of divine love.

"Whoever has experienced the merciful love of God becomes an ardent witness, especially in confrontations with those who are still caught in the nets of sin," said the Holy Father, when he addressed some 5,000 pilgrims gathered today in Paul VI Hall for the general audience.

The Pope's meditation was a further reflection on the history of love between God and man, in which the betrayal of the sinner is also present. Man is in need of an interior transformation, which can only be effected by the Holy Spirit.

In fact, the change brought about in the repentant sinner is "comparable to a new creation," the Pope said.

Just as in "the beginning, God breathed his spirit in matter and gave origin to the human person, so now the same divine Spirit re-creates, renews, transfigures and transforms the repentant sinner, embraces him once again, and renders him a participant of the joy of salvation," he continued.

Thus man, "animated by the divine Spirit, undertakes the path of justice and love," the Pope added.

"Having experienced this interior birth, the man of prayer becomes a witness" of the love of God, the Holy Father emphasized. In the Miserere, for example, the believer promises God to "teach the wicked your ways," so that "like the prodigal son, [they] will be able to return to the house of the Father," John Paul II emphasized.

However, conscious of his fragility, the Psalmist cries out to God: "Deliver me from bloodguiltiness, O God, thou God of my salvation." It is an invocation, the Pope said, which expresses "the desire for purification from evil, from violence, from hatred always present in the human heart with dark and malicious force."

The passage of Psalm 50(51) ends with a commitment to proclaim the "justice" of God.

The term "justice," John Paul II clarified, "does not properly designate the punitive action of God in confrontations with evil, but, rather, indicates the rehabilitation of the sinner, because God manifests his justice by rendering sinners righteous. God derives no pleasure from the death of the wicked, but wishes that he change his ways and live."

Thus the Holy Father continued with the series of meditations he has dedicated, for over a year, to the Psalms and canticles of the Old Testament, which have become part of the daily prayer of Christians. They may be consulted on ZENIT's Web page under the "Wednesday's Audience" section.