An Excerpt from Unlocking the Meaning of LOST: An Unauthorized Guide by Lynnette Porter and David Lavery.
Each character symbolically dies in the crash and is reborn on the island. Other scenes of death and rebirth are sprinkled throughout the first season's episodes, perhaps most blatantly in "The Moth" (Ep: 1x7, The Moth). In this episode, Locke, in his role as Charlie's temporary spiritual advisor, provides the parable of the moth, explaining that butterflies are flashy and get everyone's attention, but moths are stronger and more valuable because they spin silk. If the cocoon is opened prematurely, the moth will be too weak to survive. But the moth that struggles out of the cocoon on its own is able to survive in the world. Locke clearly believes Charlie is a moth and slowly convinces him he is much stronger than he believes.
When Charlie is entombed with Jack during a cave-in, Charlie sees a moth flying toward the top of the cave. He follows the moth toward the light and pushes his way through the earth into the sunlight. The camera focuses on Charlie's forearm struggling through the soil until it pushes free, looking very much like a horror movie shot of the undead rising from a fresh grave. The heavy handed symbolism illustrates Charlie's growing faith in himself without drugs; he is able to save himself and Jack by finding another way out of the caves. Charlie the addict "dies," and a drug-free man struggles to be reborn.
Charlie also is the focus of another death/rebirth scenario in "Raised by Another" (Ep: 1x10, Raised by Another). Jack and Kate find Charlie hanging, apparently left for dead by Ethan. Jack desperately performs CPR for so long and with such violence that Kate begs Jack to stop. Charlie appears long dead, and Kate sobs not only for his loss but for Jack's inability to let go. With a final effort, Jack pounds life into the young man, whose loud gasp again suggests the undead coming back to life.
Jack also facilitates Rose's rebirth. In the pilot episode (Ep: 1x1, Pilot Part 1), Jack corrects Boone's CPR technique. Rose also seems beyond help, but through Jack's persistent efforts comes back to life and suffers no permanent damage from her brush with death.
In Season Two, even Sawyer is the catalyst for rebirth. When Michael nearly drowns, Sawyer performs CPR and mouth-to-mouth resuscitation until Michael comes back to life (Ep: 2x2, Adrift).
Even the death of the first main character parallels a birth. Boone's death scene is inter cut with scenes of the birth of Claire's baby. As Jack cries over Boone's body, Clarie's face shines with tears of joy (Ep: 1x20, Do No Harm). The cycle of life continues, with birth and death being closely related.
The Christian concept of being born again, or "saved," even affects characters who do not seek redemption and most likely doubt that they are spiritually saved. When self-proclaimed sinner Sawyer awakens from delirium to find himself in a bunk bed inside the Hatch, he believes the castaways have been rescued. Kate assures him that they are still on the island and finally takes him outside the Hatch to prove it. "We're not saved?" Sawyer mournfully asks. "Not yet," Kate replies. Although the two outlaws have not yet sought redemption, Lost's writers imply that spiritual rebirth-being saved-is possible even for those who so far have not embraced their second chance for a new life.
Lost emphasizes that these people, armed with knowledge of their past mistakes, have been given a second chance. They do not have to share their past indiscretions with the other survivors; they need only reveal what they wish others to know. As they learn even from their experiences since the crash, they continue to grow spiritually. Nevertheless, many survivors return to old behavioral patters. Rebirth, like other spiritual events, is not easy; it requires struggle for a new life to survive.
©2006 Lynnette Porter and David Lavery, reprinted with permission from Sourcebooks. Unlocking the Meaning of LOST: An Unauthorized Guide

