Matthew 7:15-17
"Look out for deceiving prophets, who approach you wearing sheep's clothing, but who are [actually] starving wolves in their hearts.
John 3:19-21
Now this is [how God's] judgment [works]: The Light [See 1:5-9] has come into the world, but people loved darkness [i.e., sin] rather than the Light, because their deeds were evil.
2 Corinthians 11:13-15
For such men are false apostles; they are deceitful workers, who disguise themselves as [true] apostles of Christ.
2 Thessalonians 2:9-11
The coming [of this lawless person] is according to the work of Satan, [and will be] attended by all kinds of powerful [i.e., miraculous] signs and false wonders,
2 Timothy 4:3-4
For the time will come when people will not tolerate sound teaching, but will assemble to themselves teachers who will satisfy what their "itching ears" want to hear.
2 Peter 2:1-2
But just as there were false prophets among the people before, there will also be false teachers among you [Christians]. They will privately teach harmful doctrines that destroy people [spiritually], by even denying [that Jesus is] the Master, [and thereby] destroying themselves quickly.