I agree with you points. If we dont accept hearsay, how can we form an idea of how, what, who god is?
Yet people using theories (like the cosmos exist, thus god exists), build views on his existence, abilities, personality, how he acts, what he likes and doesn't like etc. They can even end up deciding if he is christian, muslim etc. They can even end up judging others for their beliefs or lack there of.
Sorry to say that it feels like filling the gap with imagination, not facts. And too big of a leap.