Just about every Vedic text speaks, in one way or another, of the two states of consciousness, the all encompassing Brahman and the immanent Atman, at times in surprisingly minute and revealing detail.
Katha puts a unique twist on this canon. It is a dialogue in which a god reveals his most intimate and closely guarded secret to a man.
First, how cool is it to have a god of death as your teacher? Then, imagine that your super cool all-powerful god of death teacher who hold your fate in his hands telling you that he has no power whatsoever over you or anyone else: the first thing Yama teaches Nishikida is that there is no such thing as death. His awesome power over all living beings, Yama teaches Nishikida, is an illusion created by the attachment of those living being to their physical bodies. It takes real balls to share with a mortal the secret that takes away your one and only divine attribute, leaving you exposed and vulnerable and, in the end, impotent. No wonder Yama begged Nishikida to take back his last wish.
In the end, the great lesson in Katha turns out to be that men and gods are no different in sharing (or, more accurately, being one and the same with) the consciousness of Brahman, no matter how this all-encompassing unity gets projected onto their inner consciousness of Atman. It is only the attainment of this knowledge that separates them.
Yeah, it's a bit of a digression from the content of the article, but I think it's still one of the coolest stories in all of religious writings.