From SBC Today: http://sbctoday.com/2012/07/19/the-lamb%E2%80%99s-book-of-life-who%E2%80%99s-in-and-who%E2%80%99s-out-by-ronnie-rogers-%E2%80%93-part-2-of-4/
[For Part 1, see http://www.evangelicalarminians.org/?q=sea.Ronnie-Rogers.The-Lambs-Book-of-Life-Whos-In-and-Whos-Out.Part-1]
What does the text not say? Neither (13:8) nor any other references to the book state the deciding factor of how names came to be in the book. Calvinists treat the passage as though it does state the determining factor, which is God’s determination to elect some to salvation, and therefore record their names; however, it does not.