Zombies, in all iterations of this myth currently, are essentially human beings reduced to the animal level of appetite. They are only hunger, only want, only aggression to feed. But they are, for this purpose, very much alive. They are animals who feed, in most cases, on human brains. They are simply reduced humans.
What is missing is awareness, consciousness, memory of who they once were, of what they once valued beyond food. They are UnLiving.
Self evidently, as far as I know zombies don’t exist, outside of, perhaps, the effects of some unholy drugs and herbal compounds. But culturally they are HUGE. They, along with vampires and werewolves, are everywhere.
To fail to affirm life, then, is to become a zombie, and life means independence of spirit, while remaining conscious of alternatives, other viewpoints, and the possibility at all times that views and ideas will need to change and evolve. Life is the capacity to respond qualitatively to a wide variety of stimuli. Death is being reduced to responding solely to hunger, and solely in response to prey.