Catechism of the Catholic Church §2133 — excerpt
"You shall love the Lord your God with all your heart, and with all your soul and with all your strength" (Deut 6:5).
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.