Catechism of the Catholic Church §2612 — excerpt
In Jesus "the Kingdom of God is at hand." He calls his hearers to conversion and faith, but also to watchfulness. In prayer the disciple keeps watch, attentive to Him Who Is and Him Who Comes, in memory of his first coming in the lowliness…
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.
Whole chapters cited: Mark 13