Rob Bell began a series on his robbellcom.tumblr.com blog entitled "What is the Bible?" in November 2013 which continued weekly until being replaced by the Robcast in January 2015. The series is excellent, so I have compiled it into an ebook for those who are so inclined. 

This edition includes the total of 75 blogs up until January 2015. Rob announces in this final blog that he will now continue with a weekly podcast, called The RobCast.

2017 Update 

Rob rewrote the tumblr series and organised it into a new book to be published by HarperCollins in May 2017 and available to order here: What-is-the-bible