"My Pippo [Pippo, born Filippo Giovannetti, was one of the young saint's dearest and most sincere friends], do you love your health? Flee, for goodness' sake, flee from what I tell you: flee from bad companions, and by these you mean not reckless, naughty, impudent young men or others; no, this would be more difficult to find, but rather those who would like to spoil your heart with beautiful words, with fake friendships. Maybe you understand me. Flee the theaters; ah, unfortunately it is true, and I know from experience, that it is a very difficult thing, indeed very difficult, to enter into them in the grace of God, and to come out without having either lost it or put it in great danger! Avoid conversations, since in such places everything conspires against our soul. Finally flee from bad books, for it is unspeakable how much harm they can do to the heart of a young person. (letter 30)"