One of the main background themes to LOST was the temple and the clear Egyptian artwork that told the stories of Death and the Afterlife.
In ancient Egypt, it was believed that a person's soul would travel a dangerous journey through the underworld. It would be tested and a final judgment would be made if it would reunite with a body in heaven. It was said that the soul would be weighed against a feather by the god of the underworld. If the soul was heavy with sin, then the soul would be condemned to hell.
So Egyptian kings and queens and royals were buried in elaborate tombs and temples to "help" them on their afterlife journey. They were buried with gold and jewels to bribe ferrymen across the River Styx. They were buried with food and wine to sustain their souls on the journey. They were at time buried with their servants who would serve and protect them.
Egyptian rulers believed that they were gods from the stars. That there final place was to return to the heavens.
There are some who believe that there may be more truth in that myth.
The ancient Egyptians built thousands of years ago the largest free standing masonry structures in the history of the planet. Massive stone blocks were moved, placed and perfectly aligned to the stars. In modern times, the largest stone supported skyscraper was 10 stories. In ancient Egypt, it was 23 stories. Modern engineers still do not know how ancient people with stone and bronze chisels could move and lift 10 ton blocks to create the massive pyramids. Even with today's heavy industrial equipment and cranes, it is doubtful that we could achieve such structures.
So the mystery of how the pyramids were constructed is joined in the religious attributes of its creators. If the ancient kings were in fact aliens from another planet with advanced technology to move large stones with ease (which would show their great power and "magic" over the human race), then our own perception of history would be false.
Beyond Egypt, there were other ancient cultures who built massive pyramid structures in harsh climates and locations. Those ancient engineers also had a detailed and accurate grasp on astrophysics and hydrodynamics to built temples and water systems which could sustain a population of more than 50,000 (which is a huge amount in ancient times).
One explanation is that our ancient forefathers were a lot smarter than we think they were. We, today, think we have the most knowledge and savvy because of our own education, experience and accomplishments. But our ancient relatives were more tuned to nature and its properties since they were more dependent on direct interaction with nature than we are today in a our processed economies. After more than tens of thousands of years of trial and error, our forefathers could have developed technology to move large stones with ease - - - something completely lost on us today.
This is not as far fetched as you might believe. In the dark middle ages, much of human knowledge was lost (it was kept alive by monks writing manuscripts). Much of the great ancient inventions were lost in the great fire of the Library of Alexandria. Those inventions may have included the first computer, navigation devices, the first automatic door and water fountains. Recall, inventors around the time of the Roman empire were magicians who entered the royal courts with fancy machines and usual feats of mechanical engineering. Leonardo had concepts of flying machines and modern tanks.
So ancient temple priests may have been the magicians of their time because they had superior knowledge. Knowledge equated to power. While much of human thought was harnessed in order to create the next superior weapon for conquest and defense (which is even true today), such knowledge could have been applied to solve the mysteries of life after death.
The pyramids could have been the launch pads for the exploration into outer space. Observation decks to the heavens or portals (physically or metaphysically or interpretive) would have been the quest of the powerful rulers who wanted "immortality" as their legacy. All major religions believe in some form of afterlife. The ancient Egyptians may have tried to find the pathway to the afterlife and bring it into their present.
Likewise, LOST's island could have been a metaphor of the quest for the pathway to immortality. A weigh station along the underworld journey of lost souls trying to reach a final judgment; to release the burdens, sins and regrets attached to their human souls. The guardians of the island were like the cults of kings who oversaw the graves and temples of ancient Egyptian rulers. They stood guard over the buried souls so the living could not disturb the dead's journey. In the LOST story line, "outsiders" like Widmore wanted to come to the island to disrupt the guardians and to take the island's power to their present. It is that grave robber dynamic that pushed the guardians, including Jacob, to recruit his own army of "followers" (including the 815 castaways) to defend the island against the likes of Widmore and his kind.