Catechism of the Catholic Church §545 — excerpt
Jesus invites sinners to the table of the kingdom: "I came not to call the righteous, but sinners." He invites them to that conversion without which one cannot enter the kingdom, but shows them in word and deed his Father's boundless mercy for them and the vast "joy in heaven over one sinner who repents".
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.