Matthew 7:15-17
"Beware of the false teachers--men who come to you in sheep's fleeces, but beneath that disguise they are ravenous wolves.
John 3:19-21
And this is the test by which men are judged--the Light has come into the world, and men loved the darkness more than they loved the Light, because their deeds were wicked.
2 Corinthians 11:13-15
For men of this stamp are sham apostles, dishonest workmen, assuming the garb of Apostles of Christ.
2 Thessalonians 2:9-11
The appearing of the Lawless one will be attended by various miracles and tokens and delusive marvels--for so Satan works--
2 Timothy 4:3-4
For a time is coming when they will not tolerate wholesome instruction, but, wanting to have their ears tickled, they will find a multitude of teachers to satisfy their own fancies;
2 Peter 2:1-2
But there were also false prophets among the people, as there will be teachers of falsehood among you also, who will cunningly introduce fatal divisions, disowning even the Sovereign Lord who has redeemed them, and bringing on themselves swift destruction.