In Revelation 20, in our reading for today, we come to the passage about the book of life being opened.
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. And the sea gave up the dead who were in it, Death and Hades gave up the dead who were in them, and they were judged, each one of them, according to what they had done. Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. And if anyone’s name was not found written in the book of life, he was thrown into the lake of fire.–Revelation 20:12-15
John Piper help us understand in an article, “What Will the Final Judgment Mean for You?”
The reason that being written in the book of life secures our salvation is that the book is called “the book of life of the Lamb who was slain” (Revelation 13:8). The names in this book are not saved on the basis of their deeds. They are saved on the basis of Christ’s being slain. He “loves us and has freed us from our sins by his blood” (Revelation 1:5). We have been ransomed by his blood (Revelation 5:9).
Knowing God through His Word ... Day by Day 