This is one of my favorite stories from the Desert Fathers and Mothers:
Abba Poemen said of Abba John the Dwarf that he had prayed God to take his passions away from him so that he might become free from care. He went and told an old man this; 'I find myself in peace, without an enemy,' he said. The old man said to him, 'Go beseech God to stir up warfare so that you may regain the affliction and humility that you used to have, for it is by warfare that the soul makes progress.' So he besought God and when warfare came, he no longer prayed that it might be taken away, but said, 'Lord, give me strength for the fight.'