CCC 338

Nothing exists that does not owe its existence to God the Creator. the world began when God's word drew it out of nothingness; all existent beings, all of nature, and all human history are rooted in this primordial event, the very genesis by which the world was constituted and time begun. Cf. St. Augustine, De Genesi adv. Man 1, 2, 4: PL — Patrologia Latina (Migne).

Read the full chapter 1. I Believe in God the Father ¶198–421