It is all of these things. A dedicated culture is built around the bible, the church, the congregation, the priests and pastors who interpret scripture and preach the 'Word' and the moral values according to both the content of the book and themselves as the ''keepers of the Word of God.''
The interpretation of a book is probably more to do with the psychology of the reader than the content of the book, but nevertheless the content itself is an important factor.
Is it?
Take two groups. Give group A one book, and group B the other. Wind forward a thousand years. Measure the difference in behaviour.
-Is there a difference between the two groups?
-If so, what are the confounding factors?
So far, we've fallen at the first fence - demonstating a difference between the two groups. All we have are two groups, one of whom occasionally plants bombs by hand, and the other which plant vastly more bombs by dropping them from aircraft. And the confounding variables appear blatent, vast and numerous.
People may feel, intuitively, that the content of the book makes some difference, but there's no evidence for it.