I'm going to reply to you anyway.
I think I understand where you are coming from, and you are not too far of the mark. If I had a one-off vision of God, I would not automatically assume that my vision was real and true. I would consider whether I might be feverish, under the influence of some substance that alters perception, sleep deprived, or possibly mentally ill. I would first assume that the vision was a figment of my imagination. You have to acknowledge that is actually the most
plausible explanation for such a vision. People hallucinate for all kinds of reasons, and see all kinds of things that are not real.
However, that automatic recourse to the most plausible explanation should not be difficult for an omnipotent God to overcome. He could appear regularly, for example, across a wider range of circumstances, and make an empirically measurable, inexplicable impact on my surroundings. Like turning my apple trees into pear trees, or making my husband's hair grow back. He could appear to a large number of witnesses, including myself.
Alternatively, of course, he could just fill me with faith in his existence, and do away with any need for such theatrics once and for all. I have observed that people who have faith in a deity are completely unconcerned that there is no evidence of any such entity actually existing. Since no God has chosen to take this choice, I can only assume that either no omnipotent gods exist, or that those that exist don't really care whether I believe in them.