Saint John Chrysostom (4th century)
Every temptation, every sorrow, every demonic assault can prove to be of great benefit for us, if we are careful and patient. The invisible enemy (the devil) pounced on Job with fierce rage and malice. But did he harm him in the end? Not at all! On the contrary, he helped Job acquire greater holiness and more glory.
When we are alert and vigilant, the devil cannot harm us. Rather, he can unintentionally help us to increase in virtue. Observe what takes place when someone blows on a fire: initially, it seems as though he is blowing it out; ultimately, however, not only does he not put out the fire, but he actually intensifies it.