It is estimated that around 5 billion copies of the Bible were sold and distributed throughout history. [1] This has happened over the course of over two thousand years. Which makes it less popular than Harry Potter (120 million copies of the first book in 20 years) or Twilight.

And that 5 billion number includes a very significant chunk of bibles which are just distributed through various religious centers (same goes for all other religious texts).

And, of course, the number of books sold says literally nothing about whether a book has stood the test of time.

[1] https://en.wikipedia.org/wiki/List_of_best-selling_books?wpr...