The Catechism in Questions & Answers

9. How are human beings to conduct themselves with respect to God’s revelations?

Human beings are to believe in God and His revelations. Only through faith can human beings grasp the divine revelations. If they believe, divine matters will be valuable to them and will define their lives.
For example, someone who does not believe in God as the Creator will not see the universe as a work of God in which the Creator has revealed Himself, but rather as the result of coincidental processes unfolding in nature.