Catechism of the Catholic Church §2754 — excerpt
The principal difficulties in the practice of prayer are distraction and dryness. the remedy lies in faith, conversion, and vigilance of heart.
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.