Matthew 7:15 NIV

1 John 4:1 NIV
Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.

2 Peter 2:1-3 NIV
But there were also false prophets among the people, just as there will be false teachers among you. They will secretly introduce destructive heresies, even denying the sovereign Lord who bought them —bringing swift destruction on themselves. Many will follow their depraved conduct and will bring the way of truth into disrepute. In their greed these teachers will exploit you with fabricated stories. Their condemnation has long been hanging over them, and their destruction has not been sleeping.

Acts 20:29-31 NIV
I know that after I leave, savage wolves will come in among you and will not spare the flock. Even from your own number men will arise and distort the truth in order to draw away disciples after them. So be on your guard! Remember that for three years I never stopped warning each of you night and day with tears.

Colossians 2:8 NIV
See to it that no one takes you captive through hollow and deceptive philosophy, which depends on human tradition and the elemental spiritual forces of this world rather than on Christ.

Deuteronomy 13:1-3 NIV
If a prophet, or one who foretells by dreams, appears among you and announces to you a sign or wonder, and if the sign or wonder spoken of takes place, and the prophet says, “Let us follow other gods” (gods you have not known) “and let us worship them,” you must not listen to the words of that prophet or dreamer. The Lord your God is testing you to find out whether you love him with all your heart and with all your soul.

Mark 13:22-23 NIV
For false messiahs and false prophets will appear and perform signs and wonders to deceive, if possible, even the elect. So be on your guard; I have told you everything ahead of time.

Matthew 24:11 NIV
and many false prophets will appear and deceive many people.