When Jesus enters the synagogue and begins teaching, all who hear him are astonished by the authority with which he teaches. Jesus' independent authority continues with the exorcism of the unclean spirit. The people are amazed that Jesus has power over the supernatural world (demons).
 
In this first chapter of his gospel, Mark has established a major theme -- the issue of Jesus' divine authority, his bringing of something radically new, and the eventual result of which will be his death. Just as putting new wine into old wineskins causes the wineskins to break and the new wine to be lost, so Jesus' bringing of the radical newness of the kingdom will lead to the breaking of the old and the spilling of his "wine" for the sake of many. The world resists God's reign, and the world's sinful resistance will lead to the death of God's own Son. Yet despite, or rather through, that death, God will fulfill his purposes.