And that they might have authority to heal diseases and to cast out demons.
Christ gives His chosen ones not only the commission to teach, but also a certain authority. This shows that their ministry was to be the continuation and testimony of His ministry. The healing of diseases and the casting out of demons were not merely extraordinary signs. They pointed to the invasion of the kingdom of God into this fallen world. Where Christ’s authority is at work, the works of sin, sickness, and demonic darkness begin to be torn down. The apostles did not receive this authority because of their personal merit or natural abilities. It was given to them from a source above them: Christ. This is an important teaching for the church in every age. True spiritual influence is not born from human strength, but from the divine calling and grace given to a person.