Scripture, the word of God, is also clear about false prophets:
Deut 18:20-22
20 But a prophet who presumes to speak in my name anything I have not commanded him to say, or a prophet who speaks in the name of other gods, must be put to death.
21 You may say to yourselves, “How can we know when a message has not been spoken by the LORD?”
22 If what a prophet proclaims in the name of the LORD does not take place or come true, that is a message the LORD has not spoken. That prophet has spoken presumptuously. Do not be afraid of him.
Jeremiah 23:16-18
16 This is what the LORD Almighty says: “Do not listen to what the prophets are prophesying to you; they fill you with false hopes. They speak visions from their own minds, not from the mouth of the LORD.
17 They keep saying to those who despise me, `The LORD says: You will have peace.’ And to all who follow the stubbornness of their hearts they say, `No harm will come to you.’
18 But which of them has stood in the council of the LORD to see or to hear his word? Who has listened and heard his word?
Ezekiel 13:1-23
1 The word of the LORD came to me:
2 “Son of man, prophesy against the prophets of Israel who are now prophesying. Say to those who prophesy out of their own imagination: `Hear the word of the LORD!
3 This is what the Sovereign LORD says: Woe to the foolish prophets who follow their own spirit and have seen nothing!
4 Your prophets, O Israel, are like jackals among ruins.
5 You have not gone up to the breaks in the wall to repair it for the house of Israel so that it will stand firm in the battle on the day of the LORD.
6 Their visions are false and their divinations a lie. They say, “The LORD declares”, when the LORD has not sent them; yet they expect their words to be fulfilled.
7 Have you not seen false visions and uttered lying divinations when you say, “The LORD declares”, though I have not spoken?
8 “`Therefore this is what the Sovereign LORD says: Because of your false words and lying visions, I am against you, declares the Sovereign LORD.
9 My hand will be against the prophets who see false visions and utter lying divinations. They will not belong to the council of my people or be listed in the records of the house of Israel, nor will they enter the land of Israel. Then you will know that I am the Sovereign LORD.
10 “`Because they lead my people astray, saying, “Peace”, when there is no peace, and because, when a flimsy wall is built, they cover it with whitewash,
11 therefore tell those who cover it with whitewash that it is going to fall. Rain will come in torrents, and I will send hailstones hurtling down, and violent winds will burst forth.
12 When the wall collapses, will people not ask you, “Where is the whitewash you covered it with?”
13 “`Therefore this is what the Sovereign LORD says: In my wrath I will unleash a violent wind, and in my anger hailstones and torrents of rain will fall with destructive fury.
14 I will tear down the wall you have covered with whitewash and will level it to the ground so that its foundation will be laid bare. When it falls, you will be destroyed in it; and you will know that I am the LORD.
15 So I will spend my wrath against the wall and against those who covered it with whitewash. I will say to you, “The wall is gone and so are those who whitewashed it,
16 those prophets of Israel who prophesied to Jerusalem and saw visions of peace for her when there was no peace, declares the Sovereign LORD.”‘
17 “Now, son of man, set your face against the daughters of your people who prophesy out of their own imagination. Prophesy against them
18 and say, `This is what the Sovereign LORD says: Woe to the women who sew magic charms on all their wrists and make veils of various lengths for their heads in order to ensnare people. Will you ensnare the lives of my people but preserve your own?
19 You have profaned me among my people for a few handfuls of barley and scraps of bread. By lying to my people, who listen to lies, you have killed those who should not have died and have spared those who should not live.
20 “`Therefore this is what the Sovereign LORD says: I am against your magic charms with which you ensnare people like birds and I will tear them from your arms; I will set free the people that you ensnare like birds.
21 I will tear off your veils and save my people from your hands, and they will no longer fall prey to your power. Then you will know that I am the LORD.
22 Because you disheartened the righteous with your lies, when I had brought them no grief, and because you encouraged the wicked not to turn from their evil ways and so save their lives, 23 therefore you will no longer see false visions or practice divination. I will save my people from your hands. And then you will know that I am the LORD.'”