Catechism of the Catholic Church §1087 — excerpt
Thus the risen Christ, by giving the Holy Spirit to the apostles, entrusted to them his power of sanctifying: they became sacramental signs of 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.