Its lamp is the Lamb.Revelation 21:23
Quietly contemplate the Lamb as the light of heaven. Light in Scripture is the emblem of joy. The joy of the saints in heaven is comprised in this: Jesus chose us, loved us, bought us, cleansed us, robed us, kept us, glorified us: We are here entirely through the Lord Jesus. Each one of these thoughts shall be as sweet as a cluster of grapes.
Light is also the cause of beauty. Nothing of beauty is left when the light is gone. Without light no radiance flashes from the sapphire, no peaceful ray proceeds from the pearl; and so all the beauty of the saints above comes from Jesus. As planets, they reflect the light of the Sun of Righteousness; they live as beams proceeding from the central orb. If He withdrew, they must die; if His glory were veiled, their glory must expire.
Light is also the emblem of knowledge. In heaven our knowledge will be perfect, but the Lord Jesus Himself will be the fountain of it. Dark providences we've never understood will then be clearly seen, and all that puzzles us now will become plain to us in the light of the Lamb. Oh, what discoveries there will be, and what glorifying of the God of love!
Light also means manifestation. Light manifests. In this world it does not yet appear what we shall be. God's people are a hidden people, but when Christ receives His people into heaven, He will touch them with the wand of His own love and change them into the image of His manifested glory. They were poor and wretched, but what a transformation! They were stained with sin, but one touch of His finger, and they are as bright as the sun and as clear as crystal. What a display! All this proceeds from the exalted Lamb. Whatever there may be of transcendent splendor, Jesus will be the center and soul of it all. Plan on being present to see Him in His own light, the King of kings and Lord of lords!