I read a book by Rick Warren..."The Purpose Driven Life".
It probably addresses some of the questions you are pursuing.
I have to offer full disclosure though.
The first time I had ever heard of Rick Warren was the buildup to the first debate between owebuma and McCain at Warren's church.
I was very disappointed at all of the support Warren provided for owebuma, not just setting up the debate, but before during and after.
I was somewhat disappointed by the book as well, but I can't tell how much of that is as a result of the dislike I fostered for Warren as a result of all his owebuma support.