Catechism of the Catholic Church §190 — excerpt
and so the Creed is divided into three parts: "the first part speaks of the first divine Person and the wonderful work of creation; the next speaks of the second divine Person and the mystery of his redemption of men; the final part speaks of…
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: Roman Catechism I, 1, 3 · St. Irenaeus, Dem. ap. 100: SCh 62, 170