There is a strong link between holiness and the sacrament of reconciliation, he said.
The true conversion of a person's heart that has opened itself to God's transformative power of renewal "is the driving force of every reform and it translates into a true evangelizing force," the Pope said.
The sacrament of reconciliation reminds people of God's limitless capacity to "transform, illuminate all the dark corners and continually open up new horizons," he said.
Through confession and God's mercy, the repentant sinner becomes a new person who is "justified, pardoned and sanctified," who can become a grace-filled and more authentic witness to God's love, he said.
"Only he who lets himself be deeply renewed by divine grace can carry in himself, and therefore proclaim, the Gospel news," he said.
"Thus each confession, from which each Christian will emerge renewed, will represent a step forward for new evangelization," he said.
Given the "educational emergency" in today's world, in which relativism has eradicated any sense that people can gradually come to know the truth and experience the truth of God, "Christians are called to proclaim with vigor the possibility of an encounter between people of today and Jesus Christ."
God became human precisely to be able to be close to all people so that they could see and hear him, he said.
That is why the sacrament of reconciliation helps a person open his or her heart and let God in. The certainty that Christ is near and will be there for humanity even when burdened by sin "is always the light of hope for the world," said the Pope.
In his address to the Pope, Portuguese Cardinal Manuel Monteiro de Castro, major penitentiary of the Apostolic Penitentiary, said priests play a major role in making sure people understand the enormous value of confession and they should be aware that they hold a "precious and irreplaceable" ministry.
The Pope echoed that sentiment urging priests to see themselves as key to helping people meet God and usher in a new beginning in their lives.
Yet priests, too, "must be the first to renew an awareness of themselves as sinners, and of their need to seek sacramental forgiveness in order to renew their encounter with Christ" and promote evangelization, he said.