Mack’s Father. William Paul Young’s most popular book is The Shack Before running away from the family farm, Mack fills Christian Faith. William Paul Young initially wrote The Shack as a way to show his children and a few close friends his religious beliefs and the path he took to spiritual fulfillment. A violent alcoholic who abused Mack and other members of his family. He suffered great loss as a child and young adult and now enjoys the wastefulness of grace with his family in the Pacific Nort