more on penance

1432
The human heart is heavy and hardened. God must give man a new heart. Conversion is first of all a work of the grace of God who makes our hearts return to him: "Restore us to thyself, O LORD, that we may be restored!" God gives us the strength to begin anew. It is in discovering the greatness of God's love that our heart is shaken by the horror and weight of sin and begins to fear offending God by sin and being separated from him. The human heart is converted by looking upon him whom our sins have pierced:
Let us fix our eyes on Christ's blood and understand how precious it is to his Father, for, poured out for our salvation, it has brought to the whole world the grace of repentance.
1433
Since Easter, the Holy Spirit has proved "the world wrong about sin,"i.e., proved that the world has not believed in him whom the Father has sent. But this same Spirit who brings sin to light is also the Consoler who gives the human heart grace for repentance and conversion.