How does one judge the reliability of people one encounters in general?
Setting aside the case where someone reporting a particular experience is well-known to the person making the judgement – as presumably in that situation one has a decent idea what the likelihood is that that person is just making random shit up.
How well does the person in question communicate? People standing on streetcorners shouting and spewing spittle on passers-by do not impress with their trustworthiness; their internet equivalent, people wandering through and posting in large chunks of all caps and with a gratuitous use of bangs, likewise.
General personal presentation: while a number of prophets are known to be the sort of people who wear their clothes to rags and lurk in deserts and the like, most of those aren’t trying to collect followings. Does the person look and behave like someone who is sane and reasonable?
What other information is available on this person, and what does it indicate about their trustworthiness or reliability? Have they been charged with tax fraud? Do they help little old ladies cross the street? Do people who know them report that they are decent folks or not? How do they respond to ridicule or hostility? Is all of this consistent with what they are purporting?
Does the person have a sense of the appropriate about communicating their experiences? Is every moment all about what their god told them to do? Are they coming across as namedropping or seeking justification from an authority to me? Do they mention it when relevant (as when someone asks about such experiences) or do they go beyond that and try to take control of situations when someone brings that sort of thing up?
What do they expect me to do about it? Someone who says, “I had this experience” I am entirely willing to agree that they believe they had this experience. Someone who wants me to do something for them, behave in a certain way, or otherwise go out of my way has to meet a much higher standard. I am of the “If your god wants me to do something, It can tell me Itself” school. If their god wants them to persuade other people to behave in a certain way, the onus is on them to actually be persuasive about it. “God said so” is not sufficient; neither is “I said so.”
For evaluating the reported stuff itself: is the stuff reported consistent with knowledge of the behaviours of that particular god, as reported in lore or pattern of other people’s experiences that are considered authoritative? If I am personally familiar with that god, is it consistent with my experiences of same? Are they making claims that are backed up by any meaningful evidence or support in the lore, and do I find those logic chains credible? Are they claiming capacities for which there can be evidence collected?
I don’t feel a great need to accept various other people as authorities; I am entirely capable of accepting other people’s personal revelations as important to them without agreeing, accepting their authority over me personally, or whatever else. I presume other people are going to make their own judgements on the matter by whatever standards satisfy them.