How does one distinguish a 'belief' from a delusion?
I'm reminded of the time I was hunting until late evening.
Go to the edge of farmers cleared fields, hit the tree line of forest that borders the river, step in and it's a whole different darker world of Fl cypress river bed. Absolutely enchanting, and worth digressing to describe.
Anyway, once in, I always just headed to the left to wherever. There was a trail coming in from the woods but that soon would fade to nothing heavily traveled or worn in from high traffic. It gets late, too late. The blood curdling evening call of the huge owls that always let me know it's time to get out of there have long past. I can see no trail, no landmarks, pretty much nothing, and I DO NOT want to spend the night there. I just figure I was still headed in the right direction because that was the direction I was headed in when it got to dark to discern where I was. I'm looking, not seeing anything that consciously tells me anything about where I am...looking aimlessly and walking, got to get out before it's pitch black. I
believe I'm headed in the right direction and also thinking it could easily be a
delusion, but I have no time to stop and think about that, I just have to get out. I come out right where I came in, and not on the trail. I met the trail just as it opened to the field. Happy Happy!...singing "We're outta' the rain, we're outta the dark, we're outta' the woods!"

How did I distinguish belief from delusion?...I don't know, but did it matter? No.
No solid idea how I did that to this day. Did God lead me out?...I doubt it, or only in that he made us like he did, and able to handle certain situations. Instinct? maybe, but what is that exactly? Was I seeing things, silhouettes of barely visible landmarks, or other clues that I wasn't conscious of seeing? Is that instinct, or is instinct something more? How does that cat that we stupidly let outside when we first move to a new place, find their way back to the old place, sometimes states away? They've never seen any of that terrain?
Whatever it is, and there may be logical explanations I don't know about, but just because we cannot distinguish how or why certain things are, or if they are, hardly means they aren't. IOW, sometimes "We just know" IS a viable explanation. We distinguish it by feelings, and there might very well be good reasons for those feeling, rendering them not actually just feelings at all, but we may not know exactly what the good reasons are. What is my proof? it happened to me and has probably happened to many in one form or another. Seeing solid result of not fully understood feelings is proof, or take the cat scenario, just to name a couple.
And don't get me wrong, I'm the last one to say we should just go by "feelings" when it comes to listening to ourselves and taking certain actions. Once we actually consciously start thinking and trying to logicate, we can mess things up thoroughly...Just as if I had stopped in the woods to try to figure out if I was wrong or right in how I was going about what I was doing, I'd a probably messed it up big time. I think, for whatever it's worth, a key there is not having time to think too deeply and mess it up with things that don't belong, just as we make split second right moves when we avoided that accident, that we might have never made had we stopped to think or had the time to stop to think. Do you realize how many split second right moves we have to make just to recover from tripping over something?...think about it...or on second thought best not or we end up flat of our @**. "Simple involuntary response...meh" but it's not all that simple, it's simply incredible, and darn near unexplainable how we do some things we do.
Though wide open for scrutiny from many angles, along with the fact, I far from fully understand it. I still think there is something to the fact that sometimes we don't have to know exactly how or why..."sometimes".