Catechism of the Catholic Church §1821 — excerpt
We can therefore hope in the glory of heaven promised by God to those who love him and do his will. In every circumstance, each one of us should hope, with the grace of God, to persevere "to the end" and to obtain the joy…
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: Council of Trent DS 1541 · St. Teresa of Avila, Excl. 15:3