You'd think it'd be easy to distinguish between the two...
Knowledge: a (1) : the fact or condition of knowing something with familiarity gained through experience or association (2) :acquaintance with or understanding of a science, art, or technique
Belief: a state or habit of mind in which trust or is placed in some person or thing
Merriam-Webster appears to sum up the two as experience vs trust. Makes sense on a practical level, but there are all kinds of experience, and there are varying levels of trust. AND - you can't experience something without trusting your senses, and you can't trust things without having some experience upon which to base that trust.
Practically speaking, we trust science. We do this because we know it's worked in the past, and we know there are people who do it professionally as well as those who pursue it merely to understand. We can look around us and see products made possible only by science. There's no doubt that science generally works.
So... how should we distinguish between knowledge and belief? More importantly, how can you tell when a person makes a claim of knowledge that should instead be a claim of belief?
Interestingly, the word "knowledge" seems intuitively to have more authority/credibility. You'll often find people claiming to know things they simply believe, but you will rarely (if ever) find people claiming to believe things they know. Belief seems to involve personal conviction, something that holds authority only with the person making the claim. You wont convince anyone of anything if your argument is merely that you believe it to be true.
Objectivity is what distinguishes knowledge from belief. If two people are able to experience the same thing and come to the same conclusion, "the ball is red" is no longer a statement of belief but a statement of knowledge.
How this ties into intellectual honesty is something I'll get into next post.