Why do some religions believe in snake handling?

Because some religion believes on inerrancy of the Bible;

Acts 28:3-8. Paul is bitten by a poisonous snake and yet lives. The "barbarians" who were shipwrecked with him thought he must be a murderer since he was bitten; but then they changed their minds and thought him to be a god since he didn't die. (The snake story is especially interesting since there are no poisonous snakes on Malta, and there is no evidence of their existence in the past.)

Numbers 21:8-9. God's cure for snakebite: a brass serpent on a pole.
To save the people from God's snakes, Moses makes a graven image in the form of a snake (breaking the second commandment) and puts it on a pole. Those who look at Moses' magic snake to not die -- even if they were previously bit by God's snakes.

Answer

There is or was a cult somewhere (in the US I believe) who mis-apply the ending of the Gospel of Mark, together with the verses mentioned above.

Mark 16:18 (King James Version)

This is clearly a case of a wrong application of a few verses of scripture, since, if this was meant to apply to all who believe the Bible to be divinely inspired, then they would all be doing it, and the snake catchers would not be able to keep up, and the hospitals would be filled with even more snake-bite victims. I understand that this cult has 'died out'. God does not honor such foolishness.

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