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Isaiah 65: 20-25 are clearly speaking of biological life, not incorruptible spirit bodies. The verses prior are predictive of NHNE, but not treating it as existing.
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Luke 24:39 Behold my hands and my feet, that it is I myself: handle me, and see; for a spirit hath not flesh and bones, as ye see me have.Perhaps a hint of what we will be like in the resurrection.
There’s no hint of division between Isaiah 65:17-19 and the rest of the chapter, so I think you’re just grasping at straws to say the prior verses do not precede the latter verses. That’s the only thing that could save your interpretation, but there is nothing in the text to suggest that, so why should we believe it unless we are already committed to your interpretation?
Verse 17 looks beyond the kingdom-age to the new heavens and the new earth (see refs. at "create"), but verses 18-25 describe the kingdom-age itself. Longevity is restored, but death, the "last enemy" 1Cor 15:26 is not destroyed till after Satan's rebellion at the end of the thousand years. Rev 20:7-14.