Catechism of the Catholic Church §1395 — excerpt
By the same charity that it enkindles in us, the Eucharist preserves us from future mortal sins. the more we share the life of Christ and progress in his friendship, the more difficult it is to break away from him by mortal sin.
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.