In the case of a person calling themselves a god, it is not only quite possible, but has occurred repeatedly through history. In Rome, Caligula called himself a god and was assassinated in a palace coup. The recently deceased leader of N. Korea was considered a deity by the countries people and he died recently as do all mortals, this time without any intervention except natural causes. As religion is banned in the country, the leader, including the current one, is considered a deity and is worshiped in veneration as such. To not do this warrants death by firing squad. The texts and codices of such individuals wind up becoming an interesting footnote to history, Though V. I, Lenin was against religion, Stalin placed the corpse of Lenin in a mausoleum for people to venerate. In this case, Lenin became deified post mortum. But if you mean a deity that is not a mortal man of history or contemporary times, then how can we kill that which we do not know.
We have within our makeup, a region in the brain that causes veneration toward something outside of ourselves, such as a deity. The problem arises when we war over resources, as has happened throughout history and this is done in the name of a deity and many innocent people are killed and harmed. This propensity toward deification also arises in cult followings of any kind of expression, such as a popular guru or a pop or movie star. They seem bigger than life, causing lessor mortals to venerate them, but they are as mortal as you and I. They too leave behind their "codices" of many forms.