Like dreams, there may be times precognition may also be communication from God. Other times...I have a theory on that. The times precognition have occurred in my life involved occurrences involving great emotion. Can emotions be so great that sometimes they are like a rock tossed into a smooth, calm lake where ripples spread out in all directions from the place the rock hit the water? Can precognition be from something like a ripple that spread from that future event back into the past? Of course, I don't know, but I've often wondered about that because, with me, strong emotion at the time of the event has always been a factor.
I understand the theory on dreams is that it is one's own brain and subconscious cleaning house (so-to-speak). Almost all my dreams have been like that, just ordinary dreams, fun to think about for a bit, but then they fade and are forgotten. They have no real message. I can only speak of my own two experiences. Right now, both dreams are as vivid in my mind as they had been when I was dreaming--and I'm speaking of decades ago. And there was a message in both and an overall sense of peace, calmness, well-being--something like that, or all combined. Hard to describe.
A great-uncle of mine (when he was quite old) wrote in his memoirs of such a dream he had had when he was about seven. It had remained vivid all of his life, and his, too, held a message. He also described that sense of well-being.
Hope this helps. It's kind of like that old saying that sometimes a cigar is just a cigar. Sometimes a dream is just a dream.