I’d wonder: a) how I managed to rule out and exhaust every natural explanation, including mental health ones, such as schizophrenia, as well as the ones I didn’t already know about, that others better versed in various disciplines do understand; b) if we are to grant that it is something that is not classically natural or known, how did I manage to rule out other such things, like ghosts or alien technology, for example, that are as equally unproven; and c) if it is indeed a “god,” why is it communicating in such a stupid, vague, indirect and ambiguous manner?
Next, and assuming we definitively identify it is some kind of “god,” I would sit down with it (probably metaphorically more than literally) and determine which one of the many recorded gods it is, if any. There would then be a very long conversation about its conduct and behaviour, during which it will need to provide satisfactory explanations for a very long list of maladies, problems design flaws and blights afflicting this world: cancer, famine, child rape, worms that eat out eyes, malaria, and so on. If these answers are satisfactory and I deem it to be benign (e.g. it is merely a scientist observing and recording the natural processes and events within our universe, in the same way we would observe animals in the wild hunting and killing each other), then it will have my respect as a fellow sentient entity, but no worship - which it would neither want nor ask for anyway. If they are not satisfactory and I deem it to be malevolent, as is the case of the “god” character in the Abrahamic myths, then I will make it clear I will create and lead an army tasked with finding a way to hunt it down and destroy it.