Against Knowledge

I hope everyone's doing well. I know that my posts have been intermittent (very intermittent) of late, but regardless, I'll get on with it. I'm going to Calvin College this coming fall, to study philosophy. I'm currently on the Calvin Campus at the 4th Annual Calvin College Undergraduate Philosophy Conference, and want to write after listening to a lecture by Jacob Heim. He wrote a paper on epistemology (theory of knowledge) and described knowledge in a traditional way. He defined it as "justified true belief," per Clifford's "Is Justified True Belief Knowledge?" Heim's argument wasn't anything particularly groundbreaking, but his discussion of several thought experiments (thanks to the help of another presenter, Alison Mirin) familiar to epistemologists brought a peculiar thought to the forefront of my brain. It is possible to have a belief (per Descartes), and it is possible to justify a belief with logic. Logic is believed because it works in what we believe to be our world and seems to be correct. Justified belief is not knowledge, but I believe that in any case, it is all that is necessary. We make decisions everyday based on justified belief. The truth of any matter is a different matter entirely. If I hold Proposition X (Px), such as "there is a computer in front of me," I can justify it and believe it. However, with my understanding of truth, I can not be sure I know it. You and I can both agree it is true, but it's possible we are in a shared delusion. The fact that such possibilities as hallucination always exist for any belief prevents me from believing anything with absolute rigor. My inability to hold a fixed belief also leads me to disbelieve my ability to know truth, or the "Way Things Are." I can't ever be sure of truth, and can never do more than guess that I believe truth, and so can never be sure that I have knowledge. I believe that my inability to be sure of my knowledge releases me from a responsibility to "know" anything. I should have justified belief- but that's all I can have, and so I shouldn't have to study truth to make decisions. Justified belief is not knowledge, but only a Good Guess, nor is it necessarily true. How can I believe it is good enough to have justified belief? I have no reason to believe I can take any more leaps than that.b