Eschatology is the study of last things, the final events in history, the ultimate destiny of humanity, the end of the world. Major issues in eschatology include the rapture, the second coming of Jesus, the tribulation, Millennialism, and the last judgment. Most of the Christian books I have read do not seriously concern themselves with eschatology, but the Left Behind series of books made it a popular topic. All twelve novels in the series made the New York Times bestselling fiction list – note: the fiction list. Prior to the Left Behind novels of the 1990s, Hal Lindsey’s 1970s bestselling books, including The Late Great Planet Earth, were also bestsellers.