The Earth during the Millenial period is still under the Curse. It is when sin is removed completely from the universe and co-signed to Hell that God’s promise of “ no more curse” will be fully and finally realized.You made a good point, and I was doubting it for a second there, but when I went back to read it over again... The New Jerusalem is what is being described in the passage you quoted, right? Since only the Church will be living in the New Jerusalem with our glorified bodies, it is accurate to say there will be no death there, even if there is death on the New Earth during the millennium. Since the resurrection has already happened for everyone that will live in the New Jerusalem at that point, it's like we have entered eternity earlier.
I don't know of quotation marks were in the original greek, but my bible translation has quotation marks talking about the New Heavens and New Earth, linking it back to Isaiah.
Look as well who is the one that shows John the New Jerusalem: it's one of the angels that was in charge of the bowl judgments during the tribulation. That would make sense if the New Jerusalem immediately follows the end of the tribulation (which ends with the bowl judgments), but not if John was seeing a vision of 1000 years after it.
There is also the matter of the tree of life being used for the healing of the nations during that time. In a world where there is absolutely no death, what would people need to be healed from?
Perhaps the Tree of Life has some other life-enhancing properties. Also, we’ll be immortal, but we’re also finite. Granted, we’ll be many times more durable than our current state, but perhaps in the throes of some extreme sport we’re playing on the New Earth we’ll acquire some sort of injury that would require a little healing. I don’t know. We won’t really know till we get there.
It may also be possible that some of us might be clever enough to concoct potions made from the Tree of Life’s leaves and fruit that grant special abilities or increase our strength a thousand-fold. I can think of some other special effects. How about temporary imperviousness to extreme heat or cold? Or a brain-boosting formula to help a man solve complex tasks that call for some complicated mental gymnastics? The possibilities are endless.