Catechism of the Catholic Church §389 — excerpt
The doctrine of original sin is, so to speak, the "reverse side" of the Good News that Jesus is the Saviour of all men, that all need salvation and that salvation is offered to all through Christ.
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.