Catechism of the Catholic Church §1253 — excerpt
Baptism is the sacrament of faith. But faith needs the community of believers. It is only within the faith of the Church that each of the faithful can believe.
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.