As I understand it the Book of Life will contain the names of every person who ever lived, except those whose names were blotted out for denying Jesus. Whereas, the Lamb’s Book of Life contains the list of all who truly accept Jesus as their savior, and whose names will never be erased. One prophecy teacher states, “When God opens this book (of life) at the Great White Throne Judgment, the only names left in it will be the names of those who have believed in Christ as Savior and Lord. That’s why the name of the book is changed from the “Book of Life” to the “Lamb’s Book of Life.” I never thought of it in this light. Will the Book of Life literally be changed into the Lamb’s Book of Life, or will there still be two separate books?
The Lamb’s Book of Life contains only the names of those who are part of the Church and inhabit the New Jerusalem (Rev. 21:27). It will be complete at the Rapture.
Since both Old Testament and Tribulation believers will have been resurrected at the 2nd Coming (Daniel 12:1-2, Rev. 20:4) the only people whose names could be written in the Book of Life at the end of the Millennium are the children of believing Tribulation survivors who will be born and come to faith during the Millennium. The two books are not the same.