Catechism of the Catholic Church §2472 — excerpt
The duty of Christians to take part in the life of the Church impels them to act as witnesses of the Gospel and of the obligations that flow from it.
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.