Sins of the flesh; the way of all flesh... The Bible is full of references that equate being human to being of the flesh. If we define humanity as of the flesh, then when we leave the flesh, we leave humanity. Unless we get fleshed bodies in the afterlife, I would think we cease to be human.
If we cease to be human when we are no longer flesh, then what will we be? I tend to think there is some essential element of “humanity” that is part of our spirits, and not just tied to our bodies. I guess I would put it, think of our current state as caterpillars, and our glorified state as butterflies. Two separate and very different forms, but the same creature, with some essential elements of its nature that doesn’t change.