Question: Could you tell me what your translation of Mark 16:15-18 is? Are believers given the power to drive out demons, speak in new tongues, pick up snakes and heal sick people?
Answer: There are two issues in this passage.
The first is that it is not included in most of the ancient manuscripts we have of the New Testament. There is little good evidence in the mind of many scholars of the New Testament to include this passage. It is also not the only offering as an ending to Mark. This raises suspicions that the text was a later addition by someone other than Mark. Other scholars, however, believe it is a valid ending to Mark.
Even if it is a valid ending to Mark, the passage does not instruct believers to pick up snakes, speak in new tongues or drive out demons. It reads, “And these signs will accompany those who believe: In my name they will drive out demons; they will speak in new tongues; they will pick up snakes with their hands; and when they drink deadly poison, it will not hurt them at all; they will place their hands on sick people, and they will get well.” The passage only describes what will happen in the lives of believers, and not necessarily what will happen in the life of every believer. When we see this played out in the book of Acts we don’t see anyone seeking out snakes to handle or poison to drink. Paul is bitten by a snake according to Acts 28:1-6, but the poison did not affect him. If the signs occur once this passage has been fulfilled.
There is enough in other portions of the Bible to indicate that healing and speaking in tongues could be an experience for believers today, but nothing is made of snake handling or drinking poison anywhere else in the Bible. To make this an essential matter of Christian practice is going beyond the Scriptures and does not do honor to Christ. If God chooses to give someone the abilities mentioned in the passage, that is His business, but the passage does not indicate that He will so choose.