Grace and Space

Lk 4:31-37
With authority: Following Jesus’ first sermon and rejection in Nazareth, Luke sends Jesus to Capernaum. His first act there is to cure a demoniac. Luke uses this section to introduce Jesus as a teacher and an exorcist, just as he introduced him as a prophet in the previous section of the Gospel (4:16-30).
As in Nazareth, Jesus is portrayed as teaching in the synagogue in Capernaum. Those who heard him respond with astonishment because he spoke with authority. The words of Jesus make a demand on the hearer/reader. Luke will demonstrate through the Gospel of what this demand consists.
The spirit of an unclean demon is no match for Jesus, who has already conquered evil in the desert (cf 4:1-13). The word with which Jesus teaches with authority is put into practice. For Luke, those who follow Jesus must also put the word into practice.
Luke demonstrates a common belief that before the day of the Lord all evil would be overcome and God would triumph over all. By portraying Jesus as an exorcist, Luke shows that the day of the Lord is at hand.