2 Peter 2:1
But there were also false prophets among the people, even as there will be false teachers among you; who will privately introduce destructive sects, denying even the Lord who bought them, bringing on themselves swift destruction.
2 Peter 2:3
And through covetousness, they will make merchandise of you, by fictitious tales: to whom the punishment threatened of old lingers not, and their destruction slumbers not.
2 Peter 2:14-19
having eyes full of the adulteress, incessantly sinning, alluring unstable souls; having a heart exercised with insatiable desires; an accursed progeny:
1 John 4:1
Beloved, do not believe every spirit, but try the spirits, whether they be from God; because many false prophets are gone forth into the world.