People who think the New Earth won’t have a sun and moon generally refer to three passages:
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. (Revelation 21:23)
There will be no more night. They will not need the light of a lamp or the light of the sun, for the Lord God will give them light. (Revelation 22:5)
The sun will no more be your light by day, nor will the brightness of the moon shine on you, for the Lord will be your everlasting light, and your God will be your glory. Your sun will never set again, and your moon will wane no more; the Lord will be your everlasting light, and your days of sorrow will end. Then will all your people be righteous and they will possess the land forever. (Isaiah 60:19-21)
Notice that none of these verses actually says there will be no more sun or moon. (Reread them carefully.) They say that the New Jerusalem will not need their light, for sun and moon will be outshone by God’s glory. The third passage says that at the time when God’s people will possess the land forever, the sun won’t set and the moon won’t wane, yet neither will dominate the sky because of God’s brighter light.
The emphasis isn’t on the elimination of sun and moon, but on their being overshadowed by the greater light of God. Who needs a reading lamp when standing under the noonday sun? Who needs the sun when the light of God’s presence pervades the city? The sun is local and limited, easily obscured by clouds. God’s light is universal, all pervading; nothing can obstruct it.
God Himself will be the light source for the New Jerusalem, restoring the original pattern that existed in Genesis 1 before the creation of sun and moon. Light preceded the light-holders, sun and moon, and apparently God’s very being provided that light (Genesis 1:3). So it will be again—another example of how the last chapters of the Bible reestablish something from the first chapters.
Isaiah tells us, “The Lord will be your everlasting light” (60:19). But John goes further, saying, “The Lamb is its lamp” (Revelation 21:23). John tells us in his Gospel that Jesus is “the true light that gives light to every man” and the light that “shines in the darkness, but the darkness has not understood it” (John 1:9, 5). He records Christ’s words, “I am the light of the world. Whoever follows me will never walk in darkness, but will have the light of life” (John8:12). And John sees what Isaiah couldn’t: The God who is the city’s light is the Messiah Himself.
Isaiah says to God, “Nations will come to your light, and kings to the brightness of your dawn” (Isaiah 60:3). The New Jerusalem will be a city illuminated not only by God’s holiness but also by His grace.