Under ancient Egyptian concepts of death, a person's soul, personality, and aspects are duplicated for a journey through the underworld to be hopefully reunited with the mummified remains in a reincarnation in paradise.
The journey through the underworld was fraught with danger. Pharoahs used their temples as blueprints for how to gain favor during their after life; the Book of the Dead contained chants, spells and magic to help one through the tests toward a final judgment.
For many fans, our patience has been tested as the show comes to its final judgment or conclusion on May 23rd. In the Egyptian myth, a person's heart was weighed against a feather on a scale. If the heart, weighed down by the burdens of sin, tipped the scale, then that person's soul would be punished in damnation. If the heart weighed less than a feather, then it was considered pure and that person's soul would be rewarded in the next realm. It is hard to imagine that a physical heart would weigh less than a feather, but it is more a metaphysical interpretation. Just like Dogen's "tests" of ash, voltage and searing fire make little sense to one seeking to confirm a diagnosis of an "infection," there has to be some final ceremony to explain LOST's mythology. It has to be more than a mere backhand good versus evil explanation, since all the characters, including Hurley, have literal blood on their hands so no one is all good and no one is all bad.