Note: Fifty Shades of Grey is a sexually explicit book. Please be aware of that before purchase
Takeaway: In spite of the explicit sex, this relatively traditional romance novel is surprisingly insightful into human behavior.
Fifty Shades of Grey (and the following two books) are a publishing wonder. Originally published by a small press last year, it was a word of mouth and mostly illegal digital copies that lead to the books being re-released by a larger publisher in April. In the last six weeks, the books have sold over 10 million copies in the US. That puts with other books like Catch-22, Lovely Bones, and Wrinkle in Time.
The difference is that Fifty Shades of Grey is very sexually explicit and includes graphic descriptions of bondage and S&M. There is a line of thought that suggests that romance novels are the female version of porn. I do not agree with that line of thought but the popularity of Fifty Shades will likely rekindle that discussion, especially among Christians.

Takeaway: The Bible was written to people very distant from us.
Summary: Tris and Four continue to have a rocky relationship and continue to try and figure out why being Divergent, like they are, is such a threat to society.
Takeaway: Everything we do changes our brains. The repetitive action of computer and internet work is very effective at changing our brains. This has implications for everything.
Takeaway: The Reformation is very important to the history of Christianity and Europe, but the mythology of the Reformation is often overplayed and detrimental to understanding modern history.
Takeaway: A reminder that we are not God. We need to submit to God and not try to get our idea of God to submit to us.
Summary: A post-World War II boarding school is the setting of a classic coming of age story.