Felix,
There really is a dividing line between belief and repeatable knowing. Mystical experiences are always anectdotal and no matter how similar we think our “mystical” experiences are, they can never be the same -ie- you cannot show me how to replicate your experience. So the skepticism remains. Did you experience a god or was it simply the result of altered brain chemistry resulting from what you had for lunch? The same goes for my experiences. Have I seen truth or is it just another bout of illusion/delusion by a befuddled brain?
At the core of agnosticism is a healthy dose of skepticism which never goes away. Ultimately, one comes to the humiliating realization that I don’t know and moreover, never will know. Such is the condition of our specie’s sentience which leaves us with an insatiable desire to know what we can’t know. The struggle is becoming comfortable with not knowing. I’m still working on that.
I don’t see any debate between believers and non-believers. Either you are or are not. The rest is just the usual squabbling as people search for their own truths.