We begin our profession of faith by saying: "I believe" or "We believe". Before expounding the Church's faith, as confessed in the Creed, celebrated in the liturgy and lived in observance of God's commandments and in prayer, we must first ask what "to believe" means. Faith is man's response to God, who reveals himself and gives himself to man, at the same time bringing man a superabundant light as he searches for the ultimate meaning of his life. Thus we shall consider first that search (Chapter One), then the divine Revelation by which God comes to meet man (Chapter Two), and finally the response of faith (Chapter Three).
Source: Catechism of the Catholic Church (Vatican.va)