I want readers to understand why the corrupt text of the KJV should not be taken lightly. According to our best manuscript evidence, Mark ends at 16:8 without a recorded resurrection appearance. Many later scribes deemed this unacceptable; so 2 different endings were tacked on to Mark by scribes. The longest ending is 16:9-20, a composite of texts from Luke and other traditions. The inauthenticity of Mark's addition is convincingly attested by its stylistic differences. Indeed, we even know who contrived it, Aristo of Pella in the mid-2nd century. This text has been party to serious harm and error. Consider this bizarre text in the KJV addition:
"And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues;
They shall take up serpents; and if they drink any deadly thing, it shall not hurt them (Mk 16:17-18)."
(1) Of the 600 million Pentecostals in our world, most believe that speaking in tongues is the indispensible condition for receiving Spirit baptism. True, speaking in tongues occurs in 3 of the 5 cases of Spirit baptism in Acts. This is not sufficient grounds for making tongues a necessary condition for Spirit baptism. But Mark's ending sets tongues apart as a unique badge of the true believer and is cited to bolster the Pentecostal case for the essential role of tongues. If this bogus KJV ending never existed, it is questionable whether tongues would ever have risen to such overinflated importance.
(2) Appalachian Christian groups cite this text as a basis for dancing with Eastern Diamonrback rattlesnakes and drinking strychnine poison as a badge of their faith in fulfillment of Jesus' promise and alleged criteria. Many have died as a result of this nonsense, but these Christians view such deaths as a test of faith. If they could only be convinced by the discoveries of Text Criticism, many lives would be saved.