NET
9 He must hold firmly to the faithful message as it has been taught, so that he will be able to give exhortation in such healthy teaching and correct those who speak against it.
Darby
9 clinging to the faithful word according to the doctrine taught, that he may be able both to encourage with sound teaching and refute gainsayers.
KJV
9 Holding fast the faithful word as he hath been taught, that he may be able by sound doctrine both to exhort and to convince the gainsayers.