Revelation 13:8
Revelation 13:88And all who dwell on the earth will worship the beast—all whose names have not been written from the foundation of the world in the Book of Life belonging to the Lamb who was slain.
Watchtower commentary reads as describing the universal worship of the political wild beast by those whose names are not in the Lamb's book of life. The "book of life" is often correlated with the 144,000 anointed Christians; on the newer two-class refinements, the great crowd is also written in for survival into paradise. The verse establishes the gulf between Jehovah's people and the world.
Pair this verse with and 21:27. There are TWO sets of books in Revelation 20: the books of deeds and the Lamb's book of life. The deeds book records sins and condemns everyone — . The Lamb's book of life records those Christ has bought by his blood — . Salvation is not by reading well in the deeds book; it is by being written in the Lamb's book. Notice the verse says "of the Lamb who was slaughtered" — the only basis for inclusion in the book of life is the slain Lamb's blood, not personal righteousness or organisational membership. The book of life is not a roster of perfectly behaved JWs; it is the register of those Christ has redeemed.