The Book of Life is a significant concept in Christian theology, representing a divine ledger in which the names of those who are granted eternal life are inscribed. This concept is rooted in various passages throughout the Bible, where it is depicted as a record maintained by God, listing those who are righteous and destined for salvation.

Biblical References:

1. Old Testament Foundations:
The idea of a divine book is first hinted at in the Old Testament. In Exodus 32:32-33, Moses intercedes for the Israelites after their sin with the golden calf, saying, "But now, please forgive their sin. But if not, then blot me out of the book You have written." The LORD responds, "Whoever has sinned against Me, I will blot out of My book." This passage suggests the existence of a heavenly record from which names can be removed due to sin.

2. Psalms and Prophets:
The Psalms also allude to this concept. Psalm 69:28 states, "May they be blotted out of the Book of Life and not listed with the righteous." This verse underscores the association of the Book of Life with righteousness and divine favor. Similarly, Daniel 12:1 speaks of a time of great distress, noting that "everyone whose name is found written in the book will be delivered."

3. New Testament Revelation:
The Book of Life is more explicitly mentioned in the New Testament, particularly in the Book of Revelation. Revelation 3:5 promises, "He who overcomes will be clothed in white garments, and I will never blot out his name from the Book of Life, but I will confess his name before My Father and His angels." This verse emphasizes the assurance of salvation for those who remain faithful.

Revelation 13:8 and 17:8 refer to those whose names are not written in the Book of Life, indicating their allegiance to the beast and their ultimate judgment. Revelation 20:12 and 20:15 describe the final judgment, where "the dead were judged according to their deeds, as recorded in the books," and "if anyone was not found written in the Book of Life, he was thrown into the lake of fire."

Finally, Revelation 21:27 declares, "But nothing unclean will ever enter it, nor anyone who practices an abomination or a lie, but only those whose names are written in the Lamb’s Book of Life," highlighting the purity and holiness required to enter the New Jerusalem.

Theological Significance:

The Book of Life is a profound symbol of God's sovereign knowledge and justice. It represents the assurance of salvation for believers, affirming that their faith and righteousness are recognized by God. The concept also serves as a warning of the consequences of sin and unbelief, as those not found in the Book of Life face eternal separation from God.

In Christian doctrine, the Book of Life underscores the importance of faith in Jesus Christ, as it is through Him that believers' names are inscribed in this divine record. The Lamb's Book of Life, as mentioned in Revelation, specifically associates this record with Christ's redemptive work, emphasizing the centrality of His sacrifice in the salvation narrative.

Overall, the Book of Life is a powerful reminder of God's grace, justice, and the eternal hope offered to those who follow Him.