Today's Gospel passage brings up several points that, though important for early Christian communities, we later Christians often overlook.
But having "authority over unclean spirits" is even more important when we remember the first miracle Jesus performs in Mark (1:21-28) is exorcising a demoniac. Each Gospel's first miracle is significant. Evangelists employ them as a way to set the theme for their Gospels.
Like everyone in his culture, Mark presumes demons cause more than just moral evil. Among other things, they're responsible for physical and psychological problems. Paralyzed or mentally ill persons are possessed; they need an exorcist to rid them of their demons. If, for instance, you woke up this morning with a bad cold, we'd presume two or three demons had somehow invaded your body during the night.
So if Mark tells his readers that Jesus' first miracle was ridding someone of a demon, he's also telling them that their task, as imitators of Jesus, is to rid this world of as much evil as they possibly can. Of course, the evangelist expects us to read the rest of his Gospel to find out how we're to go about this eradication.
The last important point in our Gospel pericope is the instruction Jesus gives the Twelve. They were to "take nothing for the journey but a walking stick -- no food, no sack, no money in their belts. They were, however, to wear sandals, but not a second tunic."
Notice how Matthew and Luke redacted the instructions they found in Mark. Matthew's missionaries, for instance, are warned not to wear sandals or take a staff. The various Gospel communities had no problem adapting Jesus' instructions to their specific needs.
The Twelve are also forbidden to "house hop." Their message is far more important than their accommodations. Neither should they waste time on those who won't listen. Unlike most Catholic pastors, they could pick their audiences.
Yet, whether the prophetic message is received or rejected, from our other two readings we presume it's always a liberating message.
In his classic book The Prophetic Imagination, Walter Brueggemann stresses that one of the main tasks of biblical prophets is to champion the freedom of God. Religious institutions traditionally restrict that freedom. God can always be approached at their sacred places, through their sacred rituals, performed by their sacred ministers -- as long as one adheres to the institution's sacred regulations. Biblical prophets, on the other hand, presume God's freedom to do whatever God wishes.
No wonder Amaziah, Bethel's high priest, wants Amos out of his shrine. This uncouth shepherd from Tekoa isn't delivering the message "shrine prophets" are expected to deliver. He's not on the priest's payroll. He's actually saying Bethel, the institution, is a hindrance to salvation.
Our Ephesians author also stresses God's freedom. This Pauline disciple proves his point by showing that, in spite of our failings, our fragile existence, or our social status, God, through the risen Jesus, is working great things through and in us.
The author compiles this "pedigree" for Gentile Christians, assuring them that Jewish Christians have no advantage over them as members of Christ's Body. All are equal, all are called, all carry on the ministry of the risen Jesus. No institution can ever limit God's plan.