Matthew 7:15
But beware of false prophets, who come to you in sheep's clothing, but within they are rapacious wolves.
2 Corinthians 11:13-15
For such false apostles, deceitful laborers, transform themselves into apostles of Christ.
Galatians 1:8-9
But if we or an angel from heaven preach you another gospel contrary to what we have preached you let him be accursed.
1 John 4:1
BELOVED, believe not every spirit, but prove the spirits whether they are of God; for many false prophets have gone out into the world.
Romans 1:21
because having known God they glorified him not as God neither were thankful, but became vain in their reasonings and their ignorant mind was darkened.