I believe we may have a fundamental disagreement on a critical matter of theology.
I am quite confident of the following: The scriptures teach that the ultimate destiny of "saved" human beings is an embodied one. In other words, we will have bodies. How can there be any doubt about this? We are told we will have a body like the resurrection body of Jesus. And that is most decidedly a "physical" thing, at least in the sense that we will have arms, legs, heads, etc. Granted, our physicality will be a transformed and perfected physicality.
But we will have bodies - this notion of our final state being one of "spirit" is entirely unBiblical.
Now, to be fair, I am not sure that you are embracing this error of believing in a "spirit-only" characterization of the final state of the redeemed human.
Now the connection of this to the matter of cremation is a separate, but related issue. For now, I will not repeat my earlier arguments; I will merely re-assert my belief that conventional burial is the better choice (not because being cremated prevents bodily resurrection, but rather because of the misleading message cremation sends to the rest of the world).