“And nothing unclean, and no one who practices abomination and lying, shall ever come into it, but only those whose names are written in the Lamb’s book of life.” Revelation 21:27
God does keep books! In fact, when David was pondering the time between his own conception and birth, he said, “in Your book were all written the days that were ordained for me, when as yet there was not one of them” (Psalm 139:16). It seems that God has a book for each person who is conceived, and that all these together constitute the Book of Life, one great volume containing the names and deeds of every one who was ever given biological life by his Maker.
But many, during the course of their lives, will reject (or simply ignore) God’s provision that would also give them eternal life. As David prayed in another Psalm: “May they be blotted out of the book of life and may they not be recorded with the righteous” (Psalm 69:28). Note also Revelation 3:5 and 22:19. And that will be a fearful thing, for “if anyone’s name was not found written in the book of life, he was thrown into the lake of fire” (Rev. 20:15).
Those whose names will not be blotted out of the book, of course, are those who have been redeemed “with precious blood, as of a lamb unblemished and spotless, the blood of Christ” (1 Pet. 1:19). Not one person deserves to be retained in God’s book, for all have sinned, but they “behold” with eyes of thankful faith “the Lamb of God who takes away the sin of the world!” (John 1:29), and have therefore been redeemed by the Lamb.
Finally only these will still have their names written on the rolls of the heavenly city. God’s Book of Life will have become “the Lamb’s book of life” on which are written forever the names of all those redeemed by His blood.