“Now there were false prophets among the people, just as there also will be false teachers among you, who will secretly introduce destructive heresies and even deny the Master who bought them, bringing swift destruction on themselves. Many people will follow their immoral ways, and because of them the way of truth will be maligned. In their greed they will exploit you with deceptive words. The ancient verdict against them is still in force, and their destruction is not delayed” (2 Pete 2.1-3).
The above verse makes us to understand that these false teachers are not going to come out from the world; rather they shall rise from among the camp of the righteous.