 The 17th and 18th verses in chapter 16 of the Gospel of Mark , the " longer ending " of disputed authenticity , formed the core of Hensley 's justification of snake handling and other miraculous activities ( he also drank poison in some services , including strychnine and battery acid ) . He interpreted the passage as a command , rather than an observation of events that occurred in the lives of some Apostles , as Christians have traditionally interpreted the verses . By handling snakes , he saw himself as part of a continuing tradition that originated in a New Testament injunction . He upheld the ability to handle venomous snakes without harm as proof of salvation and evidence of steadfast faith , linking the practice to speaking in tongues . To him , snake handling was a modern @-@ day confirmation of God 's power to supernaturally deliver people from harm . He often cast snakes as a representation of the Devil and interpreted the legal difficulties he encountered as religious persecution . He labeled those who rejected the observance of snake handling " unbelievers " . 
