God highly esteems these works…done for him in aridity and hardship, for by such means the virtues and gifts are acquired in a high degree. Those acquired through this labor are for the most part more select, refined, and stable than if they were obtained with spiritual relish and enjoyment, for virtue takes root in dryness, difficulty, and labor, as God says to St. Paul: Virtue is made prefect in weakness.
– St. John of the Cross