Can our names be erased from the Lamb's Book of Life? Revelation 3:5

Sometimes I hear people say that God writes our name in the Lamb's book of life when we trust Christ as our Savior, but if we sin too much or turn away from Christ, God erases our name. The verse usually referenced for this is Revelation 3:5. But is this what is being taught?

Christ is speaking to the "angel of the Church in Sardis" (3:1). After giving them a warning to "wake up" (v 2), He says that a "few" in Sardis are "worthy" to "walk with me in white" (v 4). He goes on to say...

"He who overcomes will thus be clothed 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)

In the context, Christ is clearly speaking about a heavenly situation. He promises that those who are "worthy" of Him will be clothed in white garments. A clear reference in believers being with Him in heaven (Revelation 7:9-14). He also says He will confess them before "the Father and His angels". Again, a reference to believers in heaven. So the "book of life" here is heavenly, not on earth. This is important to understand because it provides the background for interpreting what Christ is promising His "overcomers", i.e., believers.

In every ancient city, there was a book of life kept by the local officials. When a child was born his or her name was written in the book of life for that city. When he or she died, that person's name was erased or blotted out, because they were no longer alive.

In a similar way, God writes the names of all those who will trust in His Son in His book of life. He did this before the world ever began (see Revelation 13:8; 17:8). What Christ is promising is that those whose names are entered in His book will never be erased. Even though we die, we are still alive, because those who have Christ have eternal life (I John 5:12).

This is therefore not a veiled threat or even a suggestion that our names could be erased for some reason. Rather Christ is promising to we who are overcomers through trust in Him, that our names will not be erased from His book, that is, we will live forever with Him! What a great and wonderful promise!