D L Moody is one of those names who are renowned for their writings and preaching as an evangelist. Though I don't know much about him as a person, I know the name is considered one of the greats of olden times (yes, I know so little that before reading the wiki link I had no idea what era he lived in!) and that as a Christian, I should at least read some of his works.
This book is very straight-talking. Moody pulls no punches when talking about sin and how it affects us. He does use humour and anecdotes to explain and help convey his meaning, so though it is a blunt book, it didn't feel like he was being accusatory or holier-than-thou.
Being written in the 19th Century, it is written in old English, and all Bible references are from the King James Version, so though it is updated, the language isn't. The other thing that stood out to me, was Moody's damnation of alcohol, and drinking at all. I'm guessing that is part of the social context, as reading about prohibition on wiki, there was a societal movement against alcohol before prohibition became law in the early 20th century. As a Christian who does drink alcohol, I don't agree that we need to abstain entirely, but if it is a problem to you as an individual, then it is certainly wise to not drink.
Overall, though, I'm glad I read the book, and am more inclined to read other books by Moody, or other evangelists of the time (eg Spurgeon).