Ap prefers the # of angels on the head of a pin view to this discussion. Pretty much nobody sees value in creating needless facets of the same thing but to these navel gazing folk like Huxley, it makes a difference. Is, isn't or are not sure. That's all that matters. Is ?
It appears you are right.
You could not know there is a god and believe in god.
You could not know there is a god and not believe in god.
But who knows that there is a god? If you think you know that, then you're a theist. If you know that there is a god, you do believe in god. I know that the moon orbits the Earth, therefore, I believe that the moon orbits the Earth. I can't very well deny the existence of the moon.