I slightly disagree with the first answer. I agree that it was about the test, but disagree on reincarnation and that there was at least innate knowledge....
The Island IMO actually house all manner of life extension, which then included all manner of time travel, hence why the ending was in fact about reincarnation, which included a glimps of the next 2004 the characters had made with a branch off from time traveling to the 19070's, before they returned to their 2007+
I think it is not so much that he didn't have any inherent knowledge, but that the knowledge may have been "blurred" or confusing, because Smoke Monster "chooses" him [again?]. So either this is where one variation from time line to time line was allowed to occur and/or if the smoke monster also chose John at some point in the last go around (meaning they are somewhat inextricably linked, as we may assume the Smoke Monster may tap-into memory/memory sensory), then the knife is telling of inherent knowledge, but one that points to the smoke monster, as opposed to being the right "Candidate". Richard I think had to of known that "knife" was a bad symbol somehow and not just the wrong symbol, because of both his immediate reaction and because this clearly becomes foreshadowing of John's fate post John existence in this go around. Other proof comes in Because You Left and Follow the Leader, as John is dead, alive (time traveling through), and being impersonated by the Smoke Monster at the same time in 2007. A future casualty loop or time fold would imply a another future to use, in order to come to "repeat" it.
So I believe that the Knife was also a symbol of importance...
I also believe though that the smoke monster was not "evil" but apart of the Island that went hand in hand with Locke's (the character, not the philosopher) whole line of thought on "proper motivation" and like in Eastern Thought, sometimes beings are disguised and/or appear in the role of the antagonist, in order to push everyone forward----> "It only ends once, everything before that is just PROGRESS." = As long as there is an Island with it's light-water in tact, life never ends (it recycles), but manifests through spiritual progress, because the fabric of the universe and all of it's time-travel is maintained through the Island processing via the FS.