2.14. Why is our resurrection necessary?

While Jesus did not explain much but it seems like dead human spirit does not have life in it like the demon, while He will give life to whoever He wishes, it sounds unjust to keep the dead evil person non-operational, and the very function of body that allows deep reasoning, choices, creatives and others seem to be reserved for the body of human. Thus to give the glory to its full purpose, our body needs a restoration, This might sound contradicting to angelic spirit that has intellect, but there have not been any doctrines about angels being smarter & freer than us, though they might know more than us.