Those whose names are written in the Lamb's book of life are the faithful people of God who belong to Christ. Revelation 13:8 and 21:27 show that this book belongs to the Lamb who was slain, meaning Jesus, and contains the names of those who have eternal life in Him.

In Philippians 4:3 Paul speaks of fellow workers "whose names are in the book of life," showing it includes all who were joined to Christ, not just Jews but also Gentile believers. Revelation 20:15 adds that anyone not found in the book of life was cast into the lake of fire, making this the ultimate mark of covenant membership and salvation.

From the fulfilled perspective, those written in the Lamb's book of life were the redeemed saints of the first century, both the faithful dead and the living who endured to the end (Revelation 3:5, Hebrews 12:22-23). Their names were secured in Christ and they inherited the New Jerusalem, while those outside represented the unbelieving, the lawless, and those who rejected the Messiah (Revelation 21:8, 27). Those who reject Christ do not have eternal life, for "He who has the Son has the life, he who does not have the Son of God does not have the life" (1 John 5:12). And Jesus promised, "He who overcomes will be clothed the same way in white garments, and I will not erase his name from the book of life, and I will confess his name before My Father and before His angels" (Revelation 3:5). This same promise is seen as far back as Daniel 12:1, where it says, "everyone who is found written in the book, will be rescued." Even Moses understood this reality, saying, "if You will forgive their sin very well, but if not, please erase me from Your book which You have written!" But the Lord replied, "Whoever has sinned against Me, I will erase him from My book" (Exodus 32:32-33).