What does it mean that God does not erase names from the book of life?

The assurance that God will not erase names from the book of life is based on the understanding of His perfect nature. God promises in Scripture that those He has chosen before the foundation of the world are secure in their salvation. This concept is often explained with the notion that God's pen has no eraser—what He has written is perfect and eternal (Revelation 3:5). This truth alleviates concerns of insecurity in salvation and reveals God's faithful commitment to His elect, who have been called according to His purpose.