Knowledge is a form of belief which is something a person or conscious being does. Truth isn't a belief but rather a quality of a proposition.The classic, common way of describing truth in terms of truth is to say that knowledge is to define knowledge as a justified, true belief.

An opinion is like a belief but where a belief would refer to one's views towards an objective proposition an opinion is subjective and thus has no objective truth value. For instance, the opinion or subjective statement, 'Ice cream tastes good,' is not an objective proposition and is neither true nor false. Ice cream might taste good to one person while not to another, which does not make a contradiction or say that one of those people is holding a false belief. Rather, a subjective statement or opinion is incomplete and relative, thus it can be elaborated into many different objective propositions each with its own truth value depending mostly on context and namely who is the speaker.

Theoratically, two people cannot both know two opposing views. For instance, I cannot know X while you know -X because one of those has to false, assuming X is a proposition not an opinion or equivocal statement. In contrast, you can have the opinion that ice cream tastes great while I have the opinion ice cream tastes bad, and more than that neither of us is wrong because the taste of ice cream is subjective or in other words a matter of opinion.

Mmfiore wrote:I believe that truth is knowledge! They are one in the same.

Isn't knowledge a subcategory of belief and truth not a subcategory of belief but rather a possible quality/value of a proposition?

For instance, you wouldn't say, I true my wife is a work, and the statement, 'the sky is blue,' has a positive knowledge value. Rather you would say I know my wife is at work, and the statement, 'the sky is blue,' has a positive truth value.

Moreover, don't you think a proposition can be true even if nobody actually knows it is true? If at some point in time every human on Earth did in fact believe that the Earth was flat, does that mean it wasn't true at the time that the Earth was not flat but of course a more spherical shape?