The theme of II John is that of false teachers. The nineteenth of the Epistles was written from Ephesus sometime around 93 AD by the apostle John; the last surviving of the 12 disciples of Jesus. They are still causing problems for the church, wandering around trying to convert people to follow them. John fears that these itinerant preachers might take advantage of the good hearted Christians, and so he warns them not to listen to those who do not speak the truth about Jesus.
II John 1:12
"Having many things to write unto you, I would not write with paper and ink: but I trust to come unto you, and speak face to face, that our joy may be full"