Catechism of the Catholic Church §166 — excerpt
Faith is a personal act - the free response of the human person to the initiative of God who reveals himself. But faith is not an isolated act.
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.