“Plutarch remarks that by Typhon was understood anything violent, unruly, and disorderly. The overflowing of the Nile was called by the Egyptians Typhon. Lower Egypt is very flat, and any mounds built along the river to prevent the frequent inundations, were called Typhonian or Taphos; hence, the origin of Typhon. Plutarch, who was a rigid, orthodox Greek, and never known to much compliment the Egyptians, testifies in his Isis and Osiris, to the fact that, far from worshipping the Devil (of which Christians accused them), they despised more than dreaded Typhon. In his symbol of the opposing, obstinate power of nature, they believed him to be a poor, struggling, half-dead divinity. Thus, even at that remote age, we see the ancients already too enlightened to believe in a personal devil. As Typhon was represented in one of his symbols under the figure of an ass at the festival of the sun’s sacrifices, the Egyptian priests exhorted the faithful worshippers not to carry gold ornaments upon their bodies for fear of giving food to the ass!
Three and a half centuries before Christ, Plato expressed his opinion of evil by saying that “there is in matter a blind, refractory force, which resists the will of the Great Artificer.” This blind force, under Christian influx, was made to see and become responsible; it was transformed into Satan! His identity with Typhon can scarcely be doubted upon reading the account in Job of his appearance with the sons of God, before the Lord. He accuses Job of a readiness to curse the Lord to his face upon sufficient provocation. So Typhon, in the Egyptian Book of the Dead, figures as the accuser. The resemblance extends even to the names, for one of Typhon’s appellations was Seth, or Seph; as Satan, in Hebrew, means an adversary. In Arabic the word is Shatana, to be adverse, to persecute; and Manetho says he had treacherously murdered Osiris and allied himself with the Shemites, the Israelites.
This may possibly have originated the fable told by Plutarch, that, from the fight between Horus and Typhon, Typhon, overcome with fright at the mischief he had caused, “fled seven days on an ass, and escaping, begat the boys Ierosolumos and Ioudaios, Jerusalem and Judea.” Referring to an invocation of Typhon-Seth, Professor Reuvens says that the Egyptians worshipped Typhon under the form of an ass; and according to him Seth “appears gradually among the Semites as the background of their religious consciousness.” The name of the ass in Coptic, AO, is a phonetic of IAO, and hence the animal became a pun-symbol.
Thus, Satan is a later creation, sprung from the overheated fancy of the Fathers of the Church. By some reverse of fortune, to which the gods are subjected in common with mortals, Typhon-Seth tumbled down from the eminence of the deified son of Adam Kadmon, to the degrading position of a subaltern spirit, a mythical demon, ass. Religious schisms are as little free from the frail pettiness and spiteful feelings of humanity as the partisan quarrels of laymen. We find a strong instance of the above in the case of the Zoroastrian reform, when Magianism separated from the old faith of the Brahmans. The bright Devas of the Veda became, under the religious reform of Zoroaster, daevas, or evil spirits, of the Avesta. Even Indra, the luminous god, was thrust far back into the dark shadow in order to show off, in a brighter light, Ahura-Mazda, the Wise and Supreme Deity.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 