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 Corinthians 11:13
Men of this stamp are false apostles, treacherous workers, disguising themselves as Apostles of Christ!
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.
1 John 4:1
Dear friends, do not trust every inspiration, but test each inspiration, to see whether it proceeds from God; because many false Prophets have gone out into the world.
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.'