Treatise Written to a Devout is a highly influential devotional work written by the fourteenth century English mystic Walter Hilton. The author notes that every Christian lives two kinds of life, by which their souls do serve and please God, and procure their own salvation; corporal and spiritual. The corporal is the life of a young Christian who "deals with worldly businesses and affairs." Christians must spend time in the corporal and work to "mortify" all unholy desires in order to graduate to the spiritual life, where they spend much time in fasting and prayer. Finally, Hilton gives advises all Christians to take faith little by little because no one becomes righteous in a day.