The god Osiris appears in the Pyramid Texts (c. 2400 B.C.E.), the earliest of Egyptian records, as the deity of the royal mortuary ritual. The ancient myths proclaim that Osiris first received renown as a good king, a peaceful leader of a higher culture in the eastern Delta, then as a powerful lord over all the Delta. Although Osiris was eventually slain by an evil being called Set, it was believed that the great king's power conquered the grave and enabled him to be resurrected. Henceforth, beginning with the pharoahs and later to all who could afford mummification, all those who paid homage to Osiris would gain eternal life.
Down through the centuries, Osiris was transformed into a veritable god of the Nile and its vegetation, growth, life, and culture. He was the husband of Isis, goddess of enchantment and magic; father of the great war god Horus; and conqueror of northern Upper Egypt with his principal city at Abydos.
The cult of Osiris was established at Abydos, where he became known as the Lord of the Death or Lord of the West, referring to his mastery over all those who had traveled "west" into the sunset of death. An initiate into the cult would be led at dusk into the lower crypt of the temple by four priests carrying torches. In a corner of the crypt was an open marble sarcophagus supported by four pillars placed upon four sphinxes. The chief priest of the mystery would advise the aspirant that no man could ever escape death, but every soul who died was also destined to be resurrected and to receive life anew. Those who would be a priest of Osiris must enter the tomb alive and await his light. He must spend the night in the coffin and enter through the door of fear to achieve mastery.
The initiate would lie down in the open sarcophagus and be left alone in the crypt. The priests would leave him a small lamp which would soon use up its reservoir of oil. From somewhere outside the tomb, he would be able to hear priests chanting his funeral song. Then he would be alone in the darkness, feeling the cold of the grave close in upon him.
Perhaps the initiate would experience a life review or begin to see colors and lights appear around him. This illumination, he believed, was the light of Osiris come to bring him visions. Some aspirants might claim to have had conversations with Isis or Osiris. Others might visualize themselves in the land of the dead, walking and talking with departed spirits and receiving special teachings from Osiris.
Those who survived the night alone in the sarcophagus were awakened by the priests who proclaimed the initiate's resurrection and who brought him refreshing food and drink. Later, at an appropriate time in the temple of Osiris, the newly initiated member of the cult would be asked to describe any visions that he experienced or any prophetic messages that he received while on the journey of light with Osiris.
The theology of Osiris that promised resurrection soon overshadowed that of the sun god Ra (Re). Ra was a creator god, fundamentally solar, a king by nature, whose theology concerned itself with the world—its origin, creation, and the laws that governed it. Osiris and his doctrines were concerned with the problems of life, death, resurrection, and an afterlife.
The cosmology of Osiris may be divided into two periods. The earliest period extended to the time of the Pyramid Texts (c. 3000 B.C.E.). He was known as a peaceful political power, an administrator of a higher culture, the unifying factor in bringing the Delta and northern Upper Egypt into one realm, the ideal husband and father, and after his death, the god of resurrection. The second period extended from the time of the Pyramid Texts to the common era when he was primarily god of the dead and king of the underworld.
According to the scholar E. A. W. Budge, "[Osiris] was the god-man who suffered, and died, and rose again, and reigned eternally in heaven. They [the Egyptians] believed that they would inherit eternal life, just as he had done." When an ancient Egyptian died, the deceased expected to appear before Osiris, who would be sitting upon his throne, waiting to pass judgment on him or her. The deceased would be led into a room by the jackal-headed god Anubis, followed by the goddess Isis, the divine enchantress, representing life, and the goddess of the underworld Nephthys, representing death. There were 42 divine judges to assess the life of the one who stood before them, and the deceased would be allowed to deny 42 misdeeds. Once the deceased had presented his or her case, Osiris indicated a large pair of balances with the heart of the deceased and the feather of truth, one in each of the pans. The god Thoth read and recorded the decision.
Standing in the shadows was a monstrous creature prepared to devour the deceased, should the feather of truth outweigh his or her heart. In those instances when the heart outweighed the feather—and few devout Egyptians could really believe that their beloved Osiris would condemn them—the deceased was permitted to proceed to the Fields of Aalu (or Iahru), the real world, where the gods lived. Because humans were the offspring of the gods, the Fields of Aalu (also known as Kherneter) offered an eternal association and loving companionship with the deities. The ancient Egyptians had no doubts about immortality. In their cosmology, an afterlife under the watchful eye of Osiris was a certainty.