One of my favorite books as a young Christian was Charles Sheldon's classic, In His Steps. This is the book that birthed the whole WWJD movement. Part of the book's charm is simply the era it was written in, the golden age of American literature. But also the book portrays a beautiful (though fictional) picture of a church revived, a church trying to follow Jesus seriously in all areas of their lives, even to the point of costly sacrifices.
But then I realized that the book does not contain the gospel. The idea that Christ died to take the punishment for sinners, and that we must respond by trusting in Christ alone to rescue us from God's wrath, is nowhere to be found in this book. It contains morals - but no gospel! It paints Jesus as our example, but not our Savior. How could I have missed that for so long?
Further troubling: the characters in the book rarely consult the Bible to learn what did Jesus do. They seem to just go with their gut to determine "what would Jesus do" in a given situation.
Then I read Wikipedia's article about Charles Sheldon, the author. Check it out, it's enlightening, and helps make sense of his gospel-less book. Sheldon had a desire for the positive transformation of society, but not by people being born again.
Jesus wouldn't write this book.