Catechism of the Catholic Church §300 — excerpt
God is infinitely greater than all his works: "You have set your glory above the heavens." Indeed, God's "greatness is unsearchable". But because he is the free and sovereign Creator, the first cause of all that exists, God is present to his creatures' inmost being: "In him we live and move and have our being."
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. Augustine, Conf: 3, 6, 11: PL 32, 688