Book excerpt: John Newton is best known as the slave trader turned hymn writer who penned the most popular English hymn in history: “Amazing Grace.” However, many Christians are less familiar with the decades he spent in relative obscurity, laboring as a “spiritual doctor” while pastoring small parishes in England. In the latest addition to Crossway’s growing Theologians on the Christian Life series, Tony Reinke introduces modern readers to Newton’s pastoral wisdom by leading them through the many sermons, hymns, and—most importantly—letters that he wrote over the course of his life. Considered by many to be one of the greatest letter writers of all time, Newton has valuable insights to offer modern Christians, especially when it comes to fusing together sound doctrine, lived experience, and godly practice. Part of the Theologians on the Christian Life series.