Note the word ‘many’; Satan does not do things by halves. When he sends false teachers into the world, he does not send one or two; he sends tens of thousands of them.
I remember years ago looking at the commentary of the late Dr John Stott on this epistle. Commenting on John’s warning not admit those who donot bring this doctrine to your house, he says this applies of course only to people who reject the incarnation. It means far more than that. By that kind of reasoning the late Dr John Stott was able to promote Protestant union with Rome. He entered into discussions with dignitaries from the Church of Rome: ‘What can we do about promoting ecumenicity and oneness with the Church of Rome and all be under the pope?’ Whatever would Stott say about this second epistle of John? Does it not say, ‘Do not receive him into your house?’ ‘Oh,’ he would reply, ‘that is only for people who deny the incarnation.’
Some translate the word ‘deceivers’ as seducers. The Greek actually comes from the term wanderers. Some people say it has to do with itinerant wandering preachers, going about corrupting who they can. Other people say the way the term developed it refers to them getting you to wander, people who will drag you into stray paths and cause you to wander.