Thomas Hooker was a prominent proponent of the doctrine of preparationism, which taught that by making use of the means of grace, a "person seeking conversion might dispose himself toward receiving God's grace." He believed that much of God's favor needed to be re-earned by men. To Hooker, sin was the most crafty of enemies, defeating grace on most occasions. He disagreed with many of the predecessor theologies of Free Grace theology, preferring a more muted view on the subject. He focused on preparation for heaven and following the moralist character.