Catechism of the Catholic Church
2098 The acts of faith, hope, and charity enjoined by the first commandment are accomplished in prayer. Lifting up the mind toward God is an expression of our adoration of God: prayer of praise and thanksgiving, intercession and petition. Prayer is an indispensable condition for being able to obey God's commandments. "[We] ought always to pray and not lose heart." 15
15 Lk 18:1.
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.