In fact the ones that I have seen and met look very convincing as Christians, they say the right things and wear right the clothes, as wolves they are very cleverly disguised. With the plethora of electronic media available today, their pernicious heresies are quickly disseminated, and sadly followed by countless millions. A quick search of Christian Pages on the web will expose hundreds of these polluters of the brethren. Scripture warns that many will follow their words. 2 Peter 2 contains a comprehensive psychological profile of these false men and women of God.
False teachers are contemptuous of authority.
Especially those who walk according to the flesh in the lust of uncleanness and despise authority. They are presumptuous, self-willed. Their ministry is marked by an absence of accountability. They are unwilling to listen to, or comply with Godly authority. If they have them, their boards are stacked with sycophants and easily manipulated people only interested in furthering their own ambitions.