I took a course in college called "European Political Thought" and one of the texts we had to read was the bible. Reading it cover to cover revealed a number of surprises to me. I had to go to church as a kid so I knew the basics but I was never very religious. The best moments in class were the uncomfortable reactions of a few of the students who were clearly quite religious.

A "massive over-investment of time", indeed, unless you are doing it for college credit ;)