The introduction talked about different Christians' opinions on what the Gospel is. It also covered what the author wanted to convey to the audience in writing this book.
Chapter 1 is called Finding the Gospel in the Bible. I haven't gotten to the meat of this chapter yet, but so far it's hitting on "what source of information we're going to use in order to answer the question" [What is the Gospel?]. There are, again, many different answers and opinions. I think the first chapter will teach you how and where to find the Gospel in the Bible.
That's all I've got for now. Tell me your opinion of what the Gospel is. Also, read this book. I think it will thoroughly benefit you.
Thanks for taking the time to read this. Xoxo,
Pinkbookworm