What is the author's style in Trial and Triumph: Stories from Church History by Richard M. Hannula?

Unlike many books, Trial and Triumph wears its biases on its sleeve. Richard Hannula is a dyed in the wool Presbyterian, which clearly and distinctly explains the heavy bias in the book. Christianity is divided into thousands of individual denominations, each with their own theological perspective and some of which contain multiple theological perspectives. And their list of Christian heroes will inevitably differ as a result of those different perspectives.