Matthew 7:15
"Beware of the false prophets who come to you in sheep's clothing, but within they are ravening wolves.
2 Corinthians 11:13-15
For such fellows are sham apostles of Christ.
Galatians 1:8-9
But even though I myself or an angel from heaven were to preach any gospel other than that which I did preach to you, let him be accursed.
1 John 4:1
Do not believe every spirit, beloved, but test the spirits to see whether they are of God; for many false prophets are gone out into the world.
Romans 1:21
For although they knew God, yet they did not glorify him as God, nor give him thanks; but became vain in their reasoning, and their senseless minds were darkened.