Though the sins of which we have been treating are those which we should avoid with most care, yet do not think that you are dispensed from vigilance in regard to venial sins. I conjure you not to be one of those ungenerous Christians who make no scruple of committing a sin because it is venial. Remember these words of Holy Scripture: "He that contemneth small things shall fall by little and little." (Ecclus. 19:1). "Do not despise venial sins because they appear trifling," says St. Augustine, "but fear them because they are numerous. Small animals in large numbers can kill a man. Grains of sand are very small, yet, if accumulated, they can sink a ship. Drops of water are very small, yet how often they become a mighty river, a raging torrent, sweeping everything before them!"

The holy Doctor goes on to observe that though no number of venial sins can constitute a mortal sin, yet these slighter failings predispose us to greater faults, which often become mortal. St. Gregory observes with equal truth that slight faults are sometimes more dangerous than greater ones, for the latter, when we behold their hideousness, awaken remorse and resolutions of amendment; but the former make less impression on us, and thus, by easily relapsing into them, we soon contract a strong habit.

Finally, venial sin, however slight, is always prejudicial to the soul. It weakens our devotion, troubles the peace of our conscience, diminishes the fervor of charity, exhausts the strength of our spiritual life, and obstructs the work of the Holy Ghost in our souls. I pray you then to do all in your power to avoid these sins, for there is no enemy too weak to harm us if we make no resistance. Slight anger, gluttony, vanity, idle words and thoughts, immoderate laughter, loss of time, too much sleeping, trivial lies or flatteries-----such are the sins against which I would particularly warn you. Great vigilance is required against offenses of this kind, for occasions of venial sin abound.