Catechism of the Catholic Church §947 — excerpt
"Since all the faithful form one body, the good of each is communicated to the others.... We must therefore believe that there exists a communion of goods in the Church.
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: St. Thomas Aquinas, Symb., 10 · Roman Catechism I, 10, 24