And I saw the dead, great and small, standing before the throne, and books were opened. Then another book was opened, which is the book of life. And the dead were judged by what was written in the books, according to what they had done.
This book is not for reminding God, as if things might escape Him by forgetfulness, but it symbolizes His predestination of those to whom eternal life shall be given. For it is not that God is ignorant, and reads in the book to inform Himself, but rather His infallible prescience is the book of life in which they are written, that is to say, known beforehand.
Augustine City of God xx.15