Temples were bult for the pharaohs as their burial chambers. But under Egyptian death practices, the temple is not just a burial place, but a large complex to continually feed the king's spirit in the after life to make sure that his journey for under ground will be complete so he can join and become part of the Sun. In order to make this journey work, priests and servants would live in the temple complex, praying and making offerings to their dead king. Inside the temple, the king is buried with all the things he would need in the after life: food, clothes, gold, women, servants, spell books and preserved organs.
It was believed that a pharoah's body and soul would separate into two distinct entities. They would journey through the after life to be reunited in the heavens. But there was great danger, as the underworld gods would attempt to thwart the king's path.
The most important clue about this ritual is the hieroglyph under the temple wall which depicts the smoke monster sitting across from Anubis, the god of the underworld. This may mean something startling to the average LOST fan. Why would the smoke monster be sitting equal, eye to eye, with a god?
Because pharaohs were considered themselves as gods, children of the most important entity, Ra, the Sun god.
Because in order to control the people, a new pharaoh often sacked the old king's temple in order to "take" full command and loyalty of his subjects. But that was not always the case. In certain dynasties, the temples were controlled by loyalists who cared and protected the temple and its occupant. But since this ruling culture and customs lasted for thousands of years, many of the pharaohs and their tombs were lost literally in the sands of time.
Which brings us back to the LOST island.
The supposition is that the island contained immortal beings trying to control it from outsiders.
The island was the lost temple of an ancient king.
It is not unusual for king's to be lost in history. For example, recently the remains of a previously unknown pharaoh who reigned more than 3,600 years ago have emerged from the desert sand at South Abydos in Sohag province, about 300 miles south of Cairo, the Egyptian antiquities ministry said.
The skeleton of Woseribre Senebkay, who appears to be one of the earliest kings of a forgotten Abydos Dynasty (1650–1600 B.C.) was found by a University of Pennsylvania expedition working with Egypt's Supreme Council of Antiquities. It rested in a four-chambered tomb amidst the fragmented debris of his coffin, funerary mask and canopic chest. Such chests were used to contain the organs of an individual.
Senebkay's tomb dates to about 1650 B.C., during Egypt's Second Intermediate Period, when central authority collapsed, giving rise to several small kingdoms. It was found close to a larger royal sarcophagus chamber, recently identified as belonging to king Sobekhotep (probably Sobekhotep I, ca. 1780 BC) of the 13th Dynasty.
Badly plundered by ancient tomb robbers, the tomb of Senebkay is modest in scale. It features a limestone burial chamber painted with images of the goddesses Nut, Nephthys, Selket, and Isis flanking Senebkay's canopic shrine.
Other texts in the tomb identify the pharaoh as the "king of Upper and Lower Egypt, Woseribre, the son of Re, Senebkay."
If the island was the transposed "lost" temple complex of a pharaoh trying to get into the after life, that makes some logical sense in the Jacob back story. If the island was the temple, then the guardian is the high priest whose duty was to protect and nourish the dead king's spirit. The priest would need to have followers, a cult, to help maintain this balance. So when Jacob brought people to this island, he was using them as substitute worshippers and offerings to the dead king.
And the smoke monster was the spirit of the disembodied pharaoh. Because of the time shifting island physics, the dead king's soul could not find its path through the underworld and became trapped on the island. It needed to reunite with its body in order to move on. So the idea that the island had to be protected was true only in the context that the people on it had to serve the purpose of getting the pharaoh to the light of the after life.
And it makes sense, since the first incident shows the historical conflict that would doom ancient Egypt. When the Romans conquered Egypt, that signaled the end of the pharaohs. On the island, the arrival of Claudia's Roman boat signaled the potential end of the pharaoh's temple. The last cult member, Crazy Mother, had to make sure the Romans did not destroy the island (temple) because the king's spirit still had a chance to live and reincarnate.
What caused the smoke monster to become mortal again was the fact that the 815 survivors broke the historical chain that bound the spirits to the island. It was the actions of the survivors that caused a chain reaction which killed off the temple priests (Jacob and Dogen), which lifted the metaphysical chains tying the pharaoh's spirit to the island. Once his cult leaders were gone, and the castaways personal sacrifices were made, the dead king's soul reunited with a human body which would allow his dream to come true: the ability to leave the island. But the way he had to leave was simple: he had to die. He had to get out of the darkness (the smoke monster form) and into the light (human form) in order to transcend into the heavens. For thousands of years, he tried to accomplish this, but the island's unique properties kept him at bay.
This was the theme the smoke monster told many of the castaways, including Locke, that they had to die in order to protect or serve the island (pharaoh). The collective spiritual energy of dead souls on the island helped the pharaoh get the critical mass to become one in the after life.
The island visitors were spiritual fuel to re-launch a lost pharaoh back into his time and place in the ancient Egyptian Pantheon.