The Church has ever proved indestructible. Her persecutors have failed to destroy her; in fact, it was during times of persecution that the Church grew more and more; while the persecutors themselves, and those whom the Church would destroy, are the very ones who came to nothing. . . . Again, errors have assailed her; but in fact, the greater the number of errors that have arisen, the more has the truth been made manifest. . . . Nor has the Church failed before the assaults of demons: for she is like a tower of refuge to all who fight against the Devil.
-St. Thomas Aquinas