CCC 833
© Libreria Editrice Vaticana Source: vatican.va
The phrase "particular church," which is the diocese (or eparchy), refers to a community of the Christian faithful in communion of faith and sacraments with their bishop ordained in apostolic succession. Cf. CD 11; CIC, cann. 368-369. These particular Churches "are constituted after the model of the universal Church; it is in these and formed out of them that the one and unique Catholic Church exists." LG 23.
Read the full chapter 3. I Believe in the Holy Spirit ¶683–1065