I was a born again evangelical Christian for 10 years. I had many, many experiences. Thee are other experiences that I cannot explain either.
The answer to that is "I don't know what happened." It is not:
It was god
It was an alien
It was a ghost
I prayed for 45 years for rescue from the most brual abuse. It never came. I prayed for many things. In all that time, no prayer was answered. Oh, I saw a lot of people say that prayers were answered.
For instance, these Mormons prayed for a guy who had Covid to recover. Indeed, he recovered, after being treated with drugs - derived from science. The people, treated with the same drug, but whom nobody had prayed for also recovered. And that's the problem with answered prayer - it can be explained in many other ways.
The kind of evidence I would accept would be:
1. Miraculous answers to prayers that cannot be explained any other way, e.g. a man growing wings as he fell out of a plane, and he was able to fly down safely.
2. Photographs and videos of the person who claimed to be God repeatedly performing miracles.
3. Someone walking through a hospital and healing everybody there.
Those things would be acceptable to me.
No, I can't prove that there is a god. But you cannot prove that there is one either, and the onus is on the one who insists there is an invisible frog in the room.
How do I know how the brain works? College courses, the reading of about 600 psychology books. The extensive study of the bible over a 10 year period. The student of religious history and comparative religion over a 15 year time period.
You might like to listen to this video about the bs that is prayer. And if you even doubt that my knowledge of the bible is what I say it is, you might purchase my book to find out.