Luke 9:1 records Jesus giving the disciples authority over demons — their failure here contrasts with that empowerment.

Luke 10:17-19 shows the disciples later rejoicing that demons submit — contrasting their earlier failure with subsequent victory.

In Matthew 17:20, Jesus explains the disciples' failure was due to little faith, adding that even tiny faith can move mountains.

In Matthew 17:16, the same story is told where the father brings the boy to the disciples who could not heal him.

In Mark 9:18, the identical account records the disciples' inability to cast out the demon from the boy.

In Matthew 17:21, Jesus adds that this kind of demon only comes out through prayer and fasting, specifying the required discipline.

In Acts 19:13-16, the sons of Sceva also fail to exorcise a demon, showing unauthorized or faithless attempts in Jesus' name are ineffective.

2 Kings 4:29 tells of Elisha sending his staff through Gehazi to raise a boy but it fails — a similar pattern of delegated authority falling short.