CCC 589 Jesus gave scandal above all when he identified his merciful conduct toward sinners with God’s own attitude toward them.1 He went so far as to hint that by sharing the table of sinners he was admitting them to the messianic banquet.2 But it was most especially by forgiving sins that Jesus placed the religious authorities of Israel on the horns of a dilemma. Were they not entitled to demand in consternation, “Who can forgive sins but God alone?”3 By forgiving sins Jesus either is blaspheming as a man who made himself God’s equal, or is speaking the truth and his person really does make present and reveal God’s name.4

CCC 1423 It is called the sacrament of conversion because it makes sacramentally present Jesus’ call to conversion, the first step in returning to the Father5 from whom one has strayed by sin.
It is called the sacrament of Penance, since it consecrates the Christian sinner’s personal and ecclesial steps of conversion, penance, and satisfaction.

CCC 1439 The process of conversion and repentance was described by Jesus in the parable of the prodigal son, the center of which is the merciful father:6 the fascination of illusory freedom, the abandonment of the father’s house; the extreme misery in which the son finds himself after squandering his fortune; his deep humiliation at finding himself obliged to feed swine, and still worse, at wanting to feed on the husks the pigs ate; his reflection on all he has lost; his repentance and decision to declare himself guilty before his father; the journey back; the father’s generous welcome; the father’s joy – all these are characteristic of the process of conversion. The beautiful robe, the ring, and the festive banquet are symbols of that new life – pure worthy, and joyful – of anyone who returns to God and to the bosom of his family, which is the Church. Only the heart Of Christ Who knows the depths of his Father’s love could reveal to us the abyss of his mercy in so simple and beautiful a way.

CCC 1443 During his public life Jesus not only forgave sins, but also made plain the effect of this forgiveness: he reintegrated forgiven sinners into the community of the People of God from which sin had alienated or even excluded them. A remarkable sign of this is the fact that Jesus receives sinners at his table, a gesture that expresses in an astonishing way both God’s forgiveness and the return to the bosom of the People of God.7

CCC 1468 “The whole power of the sacrament of Penance consists in restoring us to God’s grace and joining us with him in an intimate friendship.”8 Reconciliation with God is thus the purpose and effect of this sacrament. For those who receive the sacrament of Penance with contrite heart and religious disposition, reconciliation “is usually followed by peace and serenity of conscience with strong spiritual consolation.”9 Indeed the sacrament of Reconciliation with God brings about a true “spiritual resurrection,” restoration of the dignity and blessings of the life of the children of God, of which the most precious is friendship with God.10

CCC 1700 The dignity of the human person is rooted in his creation in the image and likeness of God (article 1); it is fulfilled in his vocation to divine beatitude (article 2). It is essential to a human being freely to direct himself to this fulfillment (article 3). By his deliberate actions (article 4), the human person does, or does not, conform to the good promised by God and attested by moral conscience (article 5). Human beings make their own contribution to their interior growth; they make their whole sentient and spiritual lives into means of this growth (article 6). With the help of grace they grow in virtue (article 7), avoid sin, and if they sin they entrust themselves as did the prodigal son11 to the mercy of our Father in heaven (article 8). In this way they attain to the perfection of charity.

CCC 1846 The Gospel is the revelation in Jesus Christ of God’s mercy to sinners.12 The angel announced to Joseph: “You shall call his name Jesus, for he will save his people from their sins.”13 The same is true of the Eucharist, the sacrament of redemption: “This is my blood of the covenant, which is poured out for many for the forgiveness of sins.”14

CCC 2795 The symbol of the heavens refers us back to the mystery of the covenant we are living when we pray to our Father. He is in heaven, his dwelling place; the Father’s house is our homeland. Sin has exiled us from the land of the covenant,15 but conversion of heart enables us to return to the Father, to heaven.16 In Christ, then, heaven and earth are reconciled,17 for the Son alone “descended from heaven” and causes us to ascend there with him, by his Cross, Resurrection, and Ascension.18

CCC 2839 With bold confidence, we began praying to our Father. In begging him that his name be hallowed, we were in fact asking him that we ourselves might be always made more holy. But though we are clothed with the baptismal garment, we do not cease to sin, to turn away from God. Now, in this new petition, we return to him like the prodigal son and, like the tax collector, recognize that we are sinners before him.19 Our petition begins with a “confession” of our wretchedness and his mercy. Our hope is firm because, in his Son, “we have redemption, the forgiveness of sins.”20 We find the efficacious and undoubted sign of his forgiveness in the sacraments of his Church.21

1 Cf. Mt 9:13; Hos 6:6.
2 Cf. Lk 15:1-2, 22-32.
3 Mk 2:7.
4 Cf. Jn 5:18; 10:33; 17:6,26.
5 Cf. Mk 1:15; Lk 15:18.
6 Cf. Lk 15:11-24.
7 Cf. Lk 15; 19:9.
8 Roman Catechism, II, V, 18.
9 Council of Trent (1551): DS 1674.
10 Cf. Lk 15:32.
11 Lk 15:11-32
12 Cf. Lk 15.
13 Mt 1:21.
14 Mt 26:28.
15 Cf. Gen 3.
16 Jer 3:19-4:1a; Lk 15:18, 21.
17 Cf. Isa 45:8; Ps 85:12.
18 Jn 3:13; 12:32; 14 2-3; 16:28; 20:17; Eph 4:9-10; Heb 1:3; 2:13.
19 Cf. Lk 15:11-32, 18:13.
20 Col 1:14; Eph 1:7.
21 Cf. Mt 26:28; Jn 20:23.