Men go forth to wonder at the height of mountains, the huge waves of the sea, the broad flow of the ocean, the course of the stars-and forget to wonder at themselves. Beware of despairing about yourself: you are commanded to put your trust in God, and not in yourself.
Saint AugustineAngels are spirits, but it is not because they are spirits that they are angels. They become angels when they are sent. For the name angel refers to their office, not their nature. You ask the name of this nature, it is spirit; you ask its office, it is that of an Angel, which is a messenger.
Saint Augustine