Catechism of the Catholic Church §2166 — excerpt
The Christian begins his prayers and activities with the Sign of the Cross: "in the name of the Father and of the Son and of the Holy Spirit.
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.