CLAIM: Jesus said, “He who overcomes will thus be clothed in white garments; and I will not erase his name from the book of life” (Rev. 3:5). Does this mean that believers can potentially lose their salvation?
RESPONSE: Jesus is not threatening—but affirming—their eternal security. Jesus is emphasizing the negative concept (i.e. being blotted out) to explain the positive security of the believer (i.e. you’ll never be blotted out). In other words, he is not threatening them (“I’m going to erase your name!”); he is encouraging them (“I would never erase your name!”). Consider a parent consoling their suffering child on a hospital bed. The parent might say, “I’m not going to leave you here to suffer alone.” Now imagine if the child interpreted this to mean that the parent was thinking about leaving them! This would be the exact opposite of what the parent was trying to communicate.
The psalmist does ask God to erase names from the book of life (Ps. 69:28), but it isn’t certain whether or not God does this. This is merely a personal request from the psalmist. In fact, the names in the book of life were recorded before the universe began (Rev. 13:8; 17:8). God would have no need to erase names that were in his own book.
Remember, Sardis was not an ideal church. In fact, Jesus offers absolutely no encouragement for this group at all. Verse 1 explains that the church of Sardis was filled with professing Christians, who aren’t truly regenerate (“You have a name that you are alive, but you are dead”). Thus to the true believers there, Jesus is making a promise to never blot out their names. But to the non-believer, he is making no such promise.