Angel to demon

We often study diligently to guard against and correct ourselves of the vices of concupiscence which belong to a sensual and animal nature, and this inward conflict which the body wages adversus carnem [Gal. 5,17] is truly a spectacle worthy of God and of His Angels. But, alas, how rarely do we use this diligence and caution to conquer spiritual vices, of which pride is the first and the greatest of all, and which, sufficed of itself to transform an Angel into a demon!