Catechism of the Catholic Church §787 — excerpt
From the beginning, Jesus associated his disciples with his own life, revealed the mystery of the Kingdom to them, and gave them a share in his mission, joy, and sufferings.
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.