A story from the Desert Fathers

When Abba Macarius was returning from the marsh to his cell one day, carrying some palm-leaves, he met the devil on the road with a scythe. The latter struck at him as much as he pleased, but in vain. The devil finally said to him, "What is your power, Macarius, that makes me powerless against you? All that you do, I do, too. You fast, and so do I. You keep vigil, and I do not sleep at all. In one thing only do you beat me." Abba Macanus asked what that was. He said, "Your humility. Because of that, I can do nothing against you."