21:23 Evidently there will be no sun and moon (and stars) in the new heaven because God's glory will illuminate the whole earth. The need for created light sources will end when the Creator Himself lives among His people. God illuminated the camp of Israel with His presence in the pillar of fire, and He lit the holy of holies with His presence between the cherubim. He will similarly dispel all darkness of all kinds in the new city. The Lamb is the radiance of the Father's glory (Heb. 1:3), but the Father is also the light (22:5).
"It truly will be the Jesus Christ Light and Power Company then."763
21:24 The city will be so bright that it provides light for the whole new creation. The identity of these nations and kings is difficult to determine. The most probable explanation seems to be that the nations are groups of believers viewed according to their old creation nationalities, which they will retain in the new creation. The kings (rulers) are probably believing kings who ruled over nations during the old creation.764These kings will bring their glory into the city, thus increasing its glory, by simply entering it, since they are glorious individuals.
21:25 In John's day cities closed their gates to keep out enemies, but there will be no enemies in the eternal state so the gates will remain open (cf. Isa. 60:11). John said the city gates will never ever close (Gr. ou me kleisthosin). These kings, therefore, may enter whenever they wish. There will be no night in the New Jerusalem because God's glory illuminates all.
21:26 The gates will admit these leaders who will bring glory and honor to God from their respective groups of followers. This is a picture of worship in the new creation.
". . . these verses reflect the ancient practice of kings and nations bringing their wealth and glory to the city of the greatest king. In the heavenly city, everyone will honor the King of kings' (see Pss. 68:29; 72:10-11; Isa. 60)."765
21:27 Only believers will enter the city. The unsaved will in no way be able to do so (Gr. ou me eiselthe; cf. 22:15). Evidently any believer will be able to enter the city since the contrast is with those whose names are not in the Lamb's book of life (i.e., the lost). This verse warns the reader that the only way to gain entrance into this city is to have one's name recorded in the Lamb's book of life (cf. 20:15).
