Catechism of the Catholic Church

1427 Jesus calls to conversion. This call is an essential part of the proclamation of the kingdom: "The time is fulfilled, and the kingdom of God is at hand; repent, and believe in the gospel." ¹⁶ In the Church's preaching this call is addressed first to those who do not yet know Christ and his Gospel. Also, Baptism is the principal place for the first and fundamental conversion. It is by faith in the Gospel and by Baptism ¹⁷ that one renounces evil and gains salvation, that is, the forgiveness of all sins and the gift of new life.

1428 Christ's call to conversion continues to resound in the lives of Christians. This second conversion is an uninterrupted task for the whole Church who, "clasping sinners to her bosom, [is] at once holy and always in need of purification, [and] follows constantly the path of penance and renewal." ¹⁸ This endeavor of conversion is not just a human work. It is the movement of a "contrite heart," drawn and moved by grace to respond to the merciful love of God who loved us first. ¹⁹

1429 St. Peter's conversion after he had denied his master three times bears witness to this. Jesus' look of infinite mercy drew tears of repentance from Peter and, after the Lord's resurrection, a threefold affirmation of love for him. ²⁰ The second conversion also has a communitarian dimension, as is clear in the Lord's call to a whole Church: "Repent!" ²¹

St. Ambrose says of the two conversions that, in the Church, "there are water and tears: the water of Baptism and the tears of repentance." ²²