Revelation 21:23 says that there will be no sun or moon shining on the earth. Will the earth be transported to heaven so God can be its light?

When Revelation 21:23 says that the glory of God will illuminate the New Jerusalem it is probably speaking figuratively, in the same way that God is said to be “its temple” in the previous verse.

These verses are talking about a change in the order of things. Whereas previously worship was organised around temples, and religious leaders, and so on, in the Kingdom it will all be centred around God. Our relationship with God will change — he will directly illuminate his people.