Matthew 7:15
Beware of false Teachers--men who come to you in the guise of sheep, but at heart they are ravenous wolves.
2 Timothy 4:3
For a time will come when people will not tolerate sound teaching. They will follow their own wishes, and, in their itching for novelty, procure themselves a crowd of teachers.
2 Peter 2:1-3
But there were false prophets also in the nation, just as there will be false teachers among you, men who will secretly introduce ruinous divisions, disowning even the Lord who bought them, and bringing speedy Ruin upon themselves.
Revelation 19:20
The Beast was captured, and with him was taken the false Prophet, who performed the marvels before the eyes of the Beast, with which he deceived those who had received the brand of the Beast and those who worshiped his image. Alive, they were thrown, both of them, into the fiery lake 'of burning sulphur.'