2 Corinthians 11:13-15
For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ.
Matthew 7:15
But beware of false prophets, who come to you in sheep's clothing, but inwardly they are rapacious wolves.
Philippians 3:2
Beware of dogs, beware of the evil workers, beware of the counterfeit circumcision.
2 Peter 2:1-3
However there were indeed false prophets among the people, as there will also be false teachers among you, whosoever shall bring in destructive heresies, even denying the Lord who bought them, bringing on themselves swift destruction.
1 John 4:1
Beloved, believe not every spirit, but prove the spirits if they are of God: because many false prophets have gone out into the world.