5 All who are victorious (who overcome/conquerors) will be clothed in white. I (Jesus) will never erase their names from the Book of Life, but I will announce before My Father and His angels that they are Mine. Revelation 3:5 (NLT).
One of the main themes of the Holy Bible is God’s call to persevere and remain faithful to Him because He is faithful (see e.g., Isaiah 49:7; Psalm 36:5; 1 Corinthians 1:9). God never promised that life would be easy. However, God promised to be with us and never leave us (Isaiah 43:2-4; Hebrews 13:5-6). God through His Holy Spirit gives faithful believers the help, power, and strength to overcome any obstacle they may face (Psalm 118:5-9).
As a reward for their faithfulness, the names of all faithful believers of God (God the Father, God the Son-Jesus Christ, and God the Holy Spirit) are listed in the Book of Life. This Book represents God's record of those who have humbly remained faithful, dependent, and obedient to Him, despite the many ups and downs of this life. All faithful believers of God are guaranteed a listing in the Book of Life (see also Luke 10:20; Philippians 4:3; Revelation 20:12, 15). Even more, God promises faithful believers a new clothing (“clothed in white”) as a sign of their victory, loyalty, and purity with God.