They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover. (Mark 16:18)
This either means we have supernatural protection if we pick up a snake, or it is symbolic of God’s protection when we encounter the devil. Since the other four signs in this list are literal, it is most probable that this means physically picking up snakes. The apostle Paul experienced this supernatural protection from a viper when he was shipwrecked on the island of Melita (Acts 28:3-5). However, this is the only recorded example of this type of protection in the New Testament.
There is no record of the disciples picking up snakes just to prove they were believers. That would be tempting God (Luke 4:9-12). This, as well as drinking any deadly thing, is a promise that if we pick up snakes accidentally or are forced into that position because of our stand for Christ, we can believe for supernatural protection.
The power that is now working in believers is the same power that worked in Christ to raise Him from the dead. Everything we have as believers in Christ comes from our union with Him. Therefore, what is true of Him is true of us too. We have come to share in His throne (Eph. 2:6), which means we partake of the authority that His throne represents and exercise divine power and dominion on this earth.
There is no place in the New Testament that tells you to ask God to do something about the devil. Instead, you are told to do something about the devil. This is because you have been delegated His authority over the works of the enemy. Let the eyes of your understanding be enlightened to His exceeding power toward you (Eph. 1:18-19). Today, take authority over the devil, and walk in victory!