Caravaggio, Saint Jerome Writing (c. 1605), Galleria Borghese. Public domain.
2 verses in the King James Version. Word study for “doctrine” →
Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son.
If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed: