Most Christians believe that the snake is evil. There is no doubt that the Bible usually paints it as a tricky, venomous critter in the Old Testament and as an incarnation of Satan in the New Testament, but that is not the only snake symbolism used in the Bible.
At the beginning of the Exodus narrative, Moses is trained to turn his staff into a fierce snake, a trick which he later uses against the Egyptians… who also seemed to know the trick, but all they could make were wussy snakes.
What’s more, though the serpent is condemned by God in the Genesis narrative, later in Moses’ story it is redeemed as part of a healing staff that was later destroyed by the icon-smashing antics of King Hezekiah.
Some linguistics scholars make connections to how snakes are referred in Genesis and Numbers to how the Seraphim (Angels) are referred to in Isaiah. The impression, at least in Isaiah’s prophecy, is that the Seraphim are fiery snakes with wings.
 Dictionaries – Baker’s Evangelical Dictionary of Biblical Theology – Serpent. http://www.biblestudytools.com/dictionary/serpent/. Retrieved 31 May 2015.
 Exodus 4:3-4
 Exodus 7:8-15
 Genesis 3:14-15
 Numbers 21:4-9
 2 Kings 18:4
 Isaiah 14:29, see Strong’s Hebrew #8314a. שָׂרָף “Saraph”. Fiery Serpent.
 Matthew 3:7, 12:34, 23:33; Luke 3:7
 Matthew 10:16;
 John 3:14
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