Books are very valuable as they help one understand the bible, the history of the Bible, or even to defend inerrancy of the Bible. Books such as 7 Reasons why we can trust the Bible do a very good job at defending the Bible. Far deeper books are out there but that one is a good introduction to inerrancy. Some here do not read any book but the Bible and I have to disagree. Granted books loaded with psychology and mans opinions over the Bible I generally toss as I have many in the last few months. Lately I gave a Dave Ramsey book away as I found ones by Crown, and Randy Alcorn to be more rooted in scripture. Also I have tossed certain success type books due to the low view of the doctrine of sufficiency and the high view of psychology. Folks always test your book by the Bible but mature Christians do read books and commentaries and theology and such books.