An even simpler question is “Do you believe god exists?”
This is a true yes/no question, unlike the above. This is the question I use to separate a theist from an atheist. If the answer is “yes” that is theism. If the answer is anything else (“no”, “maybe”, “I don’t know”) then that is atheism.
I answered no, inferring from the third option which mentions belief that this is a question about belief, and not about knowledge, in which case it becomes analogous to the true yes/no question “Do you believe god exists?”
I don’t believe god exists because I have no evidence that god exists.
The other question you can ask is “do you know god exists?” Questions of knowledge are more difficult. Consider the two questions: “do you believe your father is your father?” and “do you know your father is your father?”
I can easily say “yes” to the first one - I’ve grown up with my father since I was a little boy, etc.
I cannot easily easy “yes” to the second one. That kind of answer would need a DNA test, for example.
(In fact, my own father couldn’t answer “yes” to such a question, when he discovered in his 30s that his father - my grandfather - was not actually his father, but a substitute in order to avoid persecution. My grandfather had to hide his identity during WW2 because, even though he was not Jewish, he was mistaken for being a Jew, and therefore his son, my father, would have been persecuted as well.)