“Jesus answered.

‘You faithless generation!

You perverse generation!

How much longer

Must I be with you?

How much longer

Must I put up with you?

Bring him here to me!’

Jesus rebuked the demon.

The demon came out of him.

The boy was cured instantly.”

ἀποκριθεὶς δὲ ὁ Ἰησοῦς εἶπεν Ὦ γενεὰ ἄπιστος καὶ διεστραμμένη, ἕως πότε μεθ’ ὑμῶν ἔσομαι; ἕως πότε ἀνέξομαι ὑμῶν; φέρετέ μοι αὐτὸν ὧδε.

καὶ ἐπετίμησεν αὐτῷ ὁ Ἰησοῦς, καὶ ἐξῆλθεν ἀπ’ αὐτοῦ τὸ δαιμόνιον, καὶ ἐθεραπεύθη ὁ παῖς ἀπὸ τῆς ὥρας ἐκείνης.

Problem solved, as Jesus cured the epileptic son.  However, he also reprimanded his disciples at the same time.  The healing of the man with the uncurable epileptic son can be found in the other synoptic gospels.  Mark, chapter 9:19-27, has an extended detailed version of this story, while Luke, chapter 9:41-42, has a short version of this story.  Jesus called them out (ἀποκριθεὶς δὲ ὁ Ἰησοῦς εἶπεν) as a faithless, corrupt, and perverse generation (Ὦ γενεὰ ἄπιστος καὶ διεστραμμένη).  Almost in desperation, he wondered how much longer he was going to be with them (ἕως πότε μεθ’ ὑμῶν ἔσομαι) and how much longer he had to bear with or put up with them (ἕως πότε μεθ’ ὑμῶν ἔσομαι).  He told them to bring the boy to him (φέρετέ μοι αὐτὸν ὧδε).  Finally, Jesus rebuked the demon (καὶ ἐπετίμησεν αὐτῷ ὁ Ἰησοῦς).  Once the demon came out of the boy (καὶ ἐξῆλθεν ἀπ’ αὐτοῦ τὸ δαιμόνιον), he was cured instantly or at that hour (καὶ ἐθεραπεύθη ὁ παῖς ἀπὸ τῆς ὥρας ἐκείνης).  There was a clear equivalence between the illness of epilepsy and demonic possession.  Once the devil or evil spirits had left the boy, he was cured of his illness.