Catechism of the Catholic Church §2083 — excerpt
Jesus summed up man's duties toward God in this saying: "You shall love the Lord your God with all your heart, and with all your soul, and with all your mind."
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.
Also cites: Luke 10:27:". · with all your strength."