What is the author's style in Mere Christianity by C. S. Lewis?

Mere Christianity was originally a set of radio scripts broadcast during World War II. As such, each chapter is around five pages long, enough space to fill up 10 minutes of radio air time. The scripts are arranged into four sub-books, each with a specific purpose. The first book lays out a logical argument in support of Christianity. The second book draws the inevitable beliefs which spring from the argument. The third explains Christian behavior, and the fourth describes what the ultimate implications of Christianity are. The sub-books flow logically from one to the next, buildling toward the climactic idea that only through Jesus Christ can humanity attain everlasting life, and thus move into the ultimate level of human evolution.