Do you have the right to be an atheist?

[Mr.wizard]

1. Theism gave birth to Theists.- No, theism is just a label we put on people who believe in gods, its not an entity that started birthing people.
2. Theism is wrong.- Have you reviewed all versions of gods and disproven every single one?
3. Theists do not exist.- Yes people who believe in god exist

1. A woman gave birth to a child in 1999.
2. I travel back to time in 1998 and kill the woman.- This is not real life, it's the plot from terminator.
3. The child doesn't exist.

{Bold mine}

1. Theism gave birth to Theists.- No, theism is just a label we put on people who believe in gods, its not an entity that started birthing people. We don't put the label "theism" on people,we put the label "theists" on people.(I meant this as an analogy - sorry for not pointing it out.)
2. Theism is wrong.- Have you reviewed all versions of gods and disproven every single one? Has any of the religion following these hundreds of gods provided with any consistent definition of a god?
3. Theists do not exist.- Yes people who believe in god exist And yet nobody knows what god is.How can they believe in god when they don't even know what god is?They only think they believe in god,they don't.So real theists do not exists,theists that "think" they follow theism only exist.

1. A woman gave birth to a child in 1999.
2. I travel back to time in 1998 and kill the woman.- This is not real life, it's the plot from terminator. My aim was to demonstrate a concept.Not to prove time travel.
3. The child doesn't exist.

Yes religions have provided definitions of god, it doesn't have to be consistent with other religions because they believe in different gods. Also their are probably as many versions of god as there are minds so unless you have conclusively proved each one wrong, you can not say that god does not exist. Whether or not you agree with the definition is irrelevant to the validity of the belief held by the person, you can not tell someone what to believe.

I realize you weren't trying to prove time travel, but I don't know what your example is supposed to show?