Question: "Is it possible for a person's name to be erased from the Book of Life?"
Answer: Revelation 22:19 says, “And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.” This verse is usually involved in two major controversies—the debate about biblical preservation, and the debate concerning eternal security. The question we will concern ourselves with is the latter. Does Revelation 22:19 mean that once a person’s name is written in the Lamb’s Book of Life, it can at some time in the future be erased? In other words, can a Christian lose his salvation?
First, Scripture is clear that a true believer is kept secure by the power of God, sealed for the day of redemption (Ephesians 4:30) and of all those whom the Father has given to the Son, He will lose none of them (John 6:39). The Lord Jesus Christ proclaimed, "I give them eternal life, and they shall never perish; no one can snatch them out of my hand. My Father, who has given them to me, is greater than all; no one can snatch them out of my Father's hand" (John 10:28-29b). If the “anyone” referred to in Revelation 22:19 are not believers, who are they? In other words, who might want to either add to or take away from the words of the Bible?
Most likely this would be done by those who only profess to be Christians and who suppose that their names are in the book of life. In fact, most of the corruptions of the Scriptures have been attempted by those who have professed some form of Christianity. Generally speaking, the two main groups who have traditionally tampered with the Revelation are pseudo-Christian cults and those who hold to very liberal theological beliefs. Many cults and theological liberals claim the name of Christ as their own, but they are not "born again"—the definitive biblical term for a Christian.
The Bible cites several examples of those who thought they were believers, but whose profession was proven to be false. In John 15, Jesus refers to them as branches that did not remain in Him, the true Vine, and therefore did not produce any fruit. We know they are false because “by their fruits you shall know them” (Matthew 7:16, 20) and true disciples will always exhibit the fruit of the Holy Spirit who resides within them (Galatians 5:22). In 2 Peter 2:22, Peter likens the false professors to dogs returning to their own vomit and the sow who “after washing herself returns to wallow in the mire” (ESV). The barren branch, the dog who returns to his own vomit, and the pig that washes herself are all symbols of those who profess to have salvation, but who have nothing more than their own righteousness to rely upon, not the righteousness of Christ which truly saves.
It is doubtful that those who have repented of their sin and been born again would willingly tamper with God's Word in this way—adding to it or taking from it. Of course we recognize that good people have sincerely held differences of opinion and belief in the area of textual criticism! But it CAN be demonstrated how cultists and liberals have repeatedly done both, "adding to" and "taking away from." Thus, we can understand God's warning as found in Revelation 22:19 in this manner: Anyone who tampers with this crucial message will find that God did not place their name in the Book of Life, will deny them access to His Holy City, and they will forfeit any expectation of all the good things He promises to His saints in this book.
Finally, from a purely logical standpoint, why would the sovereign and omniscient God—He who knows the end from the beginning (Isaiah 46:10)—write a name in the Book of Life when He knows He will only have to erase it when that person eventually apostatizes and denies the faith? Additionally, if you read this warning within the context of the paragraph in which it appears—Revelation 22:6-19—you can clearly see God remains consistent in His theology: only those who have taken heed of His warnings, repented and been born again, will have any good to look forward to in eternity. All others, sadly, have a terrible and terrifying future awaiting them.