Chapter 2 — Part I: The Creed — Introduction on Faith and the Creed
Section 3. Necessity Of Faith — That faith thus understood is necessary to salvation no man can reasonably doubt, particularly since it is written: Without faith it is impossible to please God. For as the end proposed to man as his ultimate happiness is far above the reach of human understanding, it was therefore necessary that it should be made known to him by God. This knowledge, however, is nothing else than faith, by which we yield our unhesitating assent to whatever the authority of our Holy Mother the Church teaches us to have been revealed by God; for the faithful cannot doubt those things of which God, who is truth itself, is the author. Hence we see the great difference that exists between this faith which we give to God and that which we yield to the writers of human history.