Jesus, whilst rounding up his earthly ministry, gave the Apostles a great task which is commonly called "The Great Commission". He moved on from that and said that there were some signs that would follow anyone who believes in Him. Apart from the fact that anyone who believes in Jesus would be saved and not be damned, there were other things that would begin to follow such persons.
These were the signs Jesus said would follow such individual -
1. They will cast out devils (Demons or unclean spirit) in Jesus' name. 2. They will speak with new tongues. (They will receive a prayer language) 3. They will be able to take up serpents. (This is divine immunity against Satanic attacks, for we know that the devil is called serpent, that old dragon - Rev 20:2) 4. Peradventure they drink any deadly thing, they will not be hurt. (This is also divine immunity). 5. They will lay hands on the sick, and the sick person will recover. (This is a supernatural ability against sickness, to bring wholeness and wellness into anyone sick)