How came this doctrine of the resurrection to be attached to the cult of Osiris and to become an integral part of Egyptian belief? There is only one answer that can be given to this: the doctrine of the resurrection was a necessary accompaniment of the practice of mummification, and Osiris was a mummified god.
We have already seen that old Babylonian hymns describe Asari or Merodach as the god "who raises the dead to life." We have also seen that Osiris was not the only mummified god known in Egypt. Ptah of Memphis was also a mummy; so too was the mummified Horus of Nekhen, who was worshipped even in the Delta in the "Arabian" nome of Goshen on the borders of Asia. Whether or not the practice of embalming first originated at Nekhen, where it was discovered that bodies buried in the nitrogenous soil of El-Kab were preserved undecayed, it is certain that, like the art of writing, it characterised the Pharaonic Egyptians from the earliest times. In no other way can we explain the existence among them of their mummified gods. But its adoption by the older races who still formed the bulk of the people was but gradual. It did not become universal before the age of the Eighteenth Dynasty.
It was not, however, the bulk of the people, but the ruling classes, who worshipped Osiris, and among whom his cult spread and grew. He became for them Un-nefer, "the good being," ready to heal for them even the pains of death, and to receive them in his realm beyond the grave, where life and action would be restored to them. The sun shone there as it did here, for was not Osiris himself a sun-god? the fields of the blessed were like those of Egypt, except that no sickness or death came near them, that no blight ever fell on fruit or corn, that the Nile never failed, and that the heat was always tempered by the northern breeze.
The "field of Alu," the Elysion of the Greeks, was at first in the marshes of the Delta near the mouths of the Nile, like the paradise of early Babylonia, which too was "at the mouth of the rivers." But it soon migrated to the north-eastern portion of the sky, and the Milky Way became the heavenly Nile. Here the dead lived in perpetual happiness under the rule of Osiris, working, feasting, reading, even fighting, as they would below, only without pain and eternally.(142)