The zombie comparison that you make is not very suitable in this case. You obviously need to read up on how states are created, simply put this happens when other states decide to treat the prospective state as a state. And as it happens a large majority of the world's states treat Palestine as a state, and there you go - statehood. Class dismissed.
U.S., allies conduct 1 air strike in Syria and 11 in Iraq against ISIS militants (Reuters)
from the article: UNESCO's Israel exhibit back on track, sort of