Revelation 21:24

24  And the nations of them which are saved shall walk in the light of it: and the kings of the earth do bring their glory and honour into it.

The nations really mean the different tribes of gentiles. All the saved will walk in the light of the Holy City. Notice that it says the kings of the earth will continue to bring their glory and honor into the Holy City so the city is not all that exists. They most likely will bring gifts into the city on special feast days. These passages seem to indicate that there is a distinction between those who live in the Holy City and the saved that dwell on the new earth.