Read Luke 9:37-42

JESUS HEALS A DEMON POSSESSED BOY
As the disciples came down from the mountain with Jesus, they passed from a reassuring experience of God’s presence to a frightening experience of evil. The beauty they had just seen must have made the ugliness seem even uglier. As our spiritual vision improves and allows us to see and understand God better, we will also be able to see and understand evil better. We would be overcome by its horror if we did not have Jesus with us to take us through it safely.
Why couldn’t the disciples cast out the evil spirit? Perhaps their faith was faltering. The battle with Satan is a difficult, ongoing struggle. Victory over sin and temptation comes through faith in Jesus Christ, not through our own efforts.