If a snake handler supposes that their ability to safely handle snakes is evidence that they're protected by the Christian god as a disciple of Jesus, then they must suppose in turn that their inability to handle snakes safely is evidence that they aren't protected by the Christian god as a disciple of Jesus. At least some part of the edifice has to take a hit.

I don't know if any non-Christian religion uses snake handling as a religious ritual. In Christianity, it's practiced in some minor denominations as an interpretation of a specific line.