Why is the Bible so short? The Old Testament checks in at about 580,000 - 590,000 words (depending on the translation), and the New Testament has about 180,000.  That means the 66 distinct books combined have a total of about 770,000 words.

For purposes of comparison, the Lord of Rings Trilogy (just 3 books!) is 525,000, Atlas Shrugged (1 book!) is 645,000, and L. Ron Hubbard's Mission Earth is over 1.2 million words.

The book of 2 John has only 245 words, and the book of 3 John has 219 words - again for comparison, Dr. Suess' Cat In The Hat 1629 words. Indeed, 12 of the 66 books are all shorter than that!

The longest book in the Bible - the Book of Psalms, has about 42,000 words, which is not too much more than 1/2 of the first Harry Potter book (80,000). 

According to Write Mindset.com, 60,000 is about the minimum for a novel, and no book in the Bible comes close. Indeed, only two of the Gospels exceed the normal maximum length of a short story by being just over 20,000.

With all of these comparisons, the point is pretty simple - the Bible is short.  The question is, Why?

Source: http://www.biblebelievers.com/believers-org/kjv-stats.html
There are several reasons, but one of the most interesting to me is the cost of available materials.  We take cheap paper for granted, but even in the days of Paul, the raw materials for writing would have been expensive.  In his Introduction to the New Testament, Raymond Brown calculated that the cost of a paper and ink alone would have cost Paul the equivalent of about US$3000 in today's money just to write the Book of Romans.  That would not have necessarily even covered the cost of an Amanuensis to physically do the writing.

With prices like that just for the raw materials, one can understand why John would say in John 21:25


  Jesus did many other things as well. If every one of them were written down, I suppose that even the whole world would not have room for the books that would be written


The truth is, he probably couldn't have afforded it!