Nachash (Hebrew, NChSh, «serpent») signifies the serpent of the Tree of Knowledge, the chief villain in Genesis of the Bible, has a particular role in Kabbalistic symbolism.
In Kabbalistic gematria the numeric value of Nachash is 358, equaled to MShICh, Meshiach or Messiah. Whether this equation was used in Gnosticism is not known, but the Gnostic held the serpent in the garden of Eden to be a Redeemer for he gave knowledge to Eve.
And, in Kabbalistic symbolism there exists a contrast between Nachash, the serpent who tempted Eve, and Nehushtan, the brazen serpent who Moses raises on a pole in the desert, also seen as the serpent of the Tree of Life. Eliphas Levi with other magical theorists have also identified Nachash as the dangerous and deceptive lower astral plane while Nehushtan with the redemptive upper astral. A.G.H.
Source:
Greer, John Michael. The New Encyclopedia of the Occult. St. Paul, MN, Llewellyn Worldwide. p. 319