These scripture readings mention a “book” that serves a heavenly record of those who will receive eternal life.

Daniel 12:1-3 “At that time Michael, the great prince who protects your people, will arise. There will be a time of distress such as has not happened from the beginning of nations until then. But at that time your people—everyone whose name is found written in the book—will be delivered. 2 Multitudes who sleep in the dust of the earth will awake: some to everlasting life, others to shame and everlasting contempt. 3 Those who are wise will shine like the brightness of the heavens, and those who lead many to righteousness, like the stars for ever and ever.

Revelation 21:22-27 I did not see a temple in the city, because the Lord God Almighty and the Lamb are its temple. 23 The city does not need the sun or the moon to shine on it, for the glory of God gives it light, and the Lamb is its lamp. 24 The nations will walk by its light, and the kings of the earth will bring their splendor into it. 25 On no day will its gates ever be shut, for there will be no night there. 26 The glory and honor of the nations will be brought into it. 27 Nothing impure will ever enter it, nor will anyone who does what is shameful or deceitful, but only those whose names are written in the Lamb’s book of life.

Luke 10:17-20 The seventy-two returned with joy and said, “Lord, even the demons submit to us in your name.” 18 He replied, “I saw Satan fall like lightning from heaven. 19 I have given you authority to trample on snakes and scorpions and to overcome all the power of the enemy; nothing will harm you. 20 However, do not rejoice that the spirits submit to you, but rejoice that your names are written in heaven.” L This is the Gospel of the