The New Testament book of Romans: This letter is credited as being one of the most profoundly influential letters for individuals and for the Church. Many Christian leaders throughout the centuries have written about the influence the Book of Romans has had on their lives. Writings from 386 AD to the present – from Aurelius Augustine, whose writings have shaped the Western Church for more than 1500 years; to the writings of Karl Barth, who became the most prolific and influential theologian o ...