The curse of the pharaohs refers to an ancient alleged curse believed by some to be cast upon any person who disturbs the tomb of an Egyptian person, especially a pharaoh or king. This curse, which does not differentiate between thieves and archaeologists, allegedly can cause bad luck, illness or death. Since the mid-20th century, many authors and documentaries have argued that the curse is real in the sense of being caused by scientifically explicable causes such as bacteria or radiation.
When a tomb is opened after hundreds of years, it contains dust and bacteria that have not seen the light of day. Those bacteria or dust can contain pathogens that modern man has no immunity form.
The Book of the Dead contained passages to ward off people from disturbing the tombs. Religious beliefs stated that those possessions in the deceased chambers were needed in the afterlife. Grave robbers knew that the rich were buried with vast treasures of gold, silver and gems.
The curse legend grew in the 1920s and 1930s when Howard Carter's archeology team uncovered the best tomb of all time, King Tut's. After excavating the tomb, several members of the team died mysterious deaths, one from a mosquito bite and one from blood poisoning.
For those who still seek a unified theory to LOST's mythology, the curse theory may be the one.
The island was filled with Egyptian references, including columns of hieroglyphs in the Temple to Jacob's textiles. And if you review LOST's elements as an allegory to ancient Egyptian rituals and practices, you can weave a good theory.
In order to protect a pharaoah's afterlife, he would have gathered loyal subjects, his priests, to make continuous offerings and to protect his tomb from raiders. These priests were powerful men in society. Many were viewed to have magical properties and direct contact with the gods.
When people do not understand what they see, they call it magic or supernatural. The magicians can use unknown science, illusion or slight of hand to deceive, manipulate or shock people. Some people know that one way to control people is to create chaos, fear or expectation of death.
We have Jacob as the island guardian. He is the high priest of the island. The island contains a temple - - - and temples were created for the specific purpose of burial of powerful people.
The smoke monster could be viewed as the deadly dust that is the manifestation of the curse for those foreigners who came to the island to disturb the temple rites.
Why did Jacob allow people to come to his island? Just as in ancient times, a pharaoh, dead or alive, needed subjects to protect him and his remains. The Flight 815 survivors could be unwittingly recruits for the pharaoh's subjects. They were placed in the way of raiders such as Widmore's men who wanted to take control (and plunder) the island.
One can see that the smoke monster's deaths were not indiscriminate. It killed people like Eko because he did not believe in the island's religion. He was wrapped up in his brother's religion out of guilt. As such, Eko had no role in protecting the temple or the island. Eko was then expendable.
Likewise, converts like Locke were used to try to recruit loyal subjects to return to the island. When he failed, he was killed because he had no value to the island high priest.
The one concept that stood the test of the series was that the island had to be protected (from the unknown). That was the reason and excuse for all the conflicting behaviors and story lines.
Just as in Egyptian mythology, the smoke monster may have evolved to rival the high priest - - - to overthrow him to create his new cult. That is why Flocke did not kill Widmore's men in mass; he used the alleged conflict between the sides in order to oust Jacob from his position of power. Flocke's background was one of science (MIB was into Roman culture and technology as a young man) while Jacob was schooled in the metaphysics of religious beliefs tied to the island's mysterious past. The theme of science vs. religion was common in the series. It seems that it was tested at various stages in time, from the military coming to the island to challenge the inhabitants to Dharma's uneasy truce with the natives. There were two different views of the island. One was to keep the religious tenets in place (Jacob). The other was to abandon the old ways (MIB) and abandon the island.
In some ways, the latter prevailed just like it did in Egypt. Egyptian cult religion or worship its pharaohs died off to be replaced with modern religions in a secular government structure (with intermittent civil wars and political upheaval.)
Just as modern archeology triumphed over the safeguards of tomb construction, LOST's major change was the loss of the island's long standing structure and purpose.
When it was said that the characters had to "let go" in order to be free, it could mean that they had to let go their own past personal principle structures (which commonly is called religious beliefs) in order to embrace their own free will and their thoughts on morality and mortality.