I wouldn't say knowledge is meaningless just relative to the reality of the realm it applies to. If an entity in that other realm can affect this realm, the only meaningful pursuit from this realm would be it's effect on this realm if any. I see your point, would you consider another dimension another realm?
"There ought to be a term that would designate those who actually follow the teachings of Jesus, since the word 'Christian' has been largely divorced from those teachings, and so polluted by fundamentalists that it has come to connote their polar opposite: intolerance, vindictive hatred, and bigotry." -- Philip Stater, Huffington Post
always working on cleaning my windows- me regarding Johari
always working on cleaning my windows- me regarding Johari