"...the Lord said to me, 'The prophets prophesy lies in My name. I have not sent them, commanded them, nor spoken to them; they prophesy to you a false vision, divination, a worthless thing, and the deceit of their heart." Jeremiah 14:14

Visions from their own hearts and imagination

"Do not listen to the words of the prophets who prophesy to you...
They speak a vision of their own heart,
Not from the mouth of the Lord.
They continually say to those who despise Me,
‘The Lord has said, 'You shall have peace’;
And to everyone who walks according to the dictates of his own heart, they say, 'No evil shall come upon you.’ ” Jeremiah 23:16-17

"I have not sent these prophets, yet they ran.
I have not spoken to them, yet they prophesied.
But if they had stood in My counsel, and had caused My people to hear My words,
Then they would have turned them from their evil way
And from the evil of their doings." Jeremiah 23:21

"They have also healed the hurt of My people slightly,
Saying, ‘Peace, peace!’ when there is no peace.
Were they ashamed when they had committed abomination?
No! They were not at all ashamed; nor did they know how to blush.
Therefore they shall fall among those who fall;
At the time I punish them, they shall be cast down,' says the Lord."  Jeremiah 6:14-15

"Woe to the shepherds who destroy and scatter the sheep of My pasture!” says the Lord." Jeremiah 23:1

"...the prophet who presumes to speak a word in My name, which I have not commanded him to speak, or who speaks in the name of other gods, that prophet shall die.’ And if you say in your heart, ‘How shall we know the word which the Lord has not spoken?’— when a prophet speaks in the name of the Lord, if the thing does not happen or come to pass, that is the thing which the Lord has not spoken; the prophet has spoken it presumptuously..." Deuteronomy 18:20-22

"Woe to you when all men speak well of you, for so did their fathers to the false prophets." Luke 6:26

"The coming of the lawless one is according to the working of Satan, with all power, signs, and lying wonders, and with all unrighteous deception among those who perish, because they did not receive the love of the truth, that they might be saved. And for this reason God will send them strong delusion, that they should believe the lie, that they all may be condemned who did not believe the truth but had pleasure in unrighteousness." 2 Thessalonians 2:9-12

"For forty years I was grieved with that generation, and said, ‘It is a people who go astray in their hearts, and they do not know My ways.’" Psalm 95:9

God's rebuke

"'Behold, I am against the prophets,' says the Lord,

"who use their tongues and say, ‘He says.’

Behold, I am against those who prophesy false dreams,' says the Lord,

'and... cause My people to err by their lies and by their recklessness.

Yet I did not send them or command them...."  Jeremiah 23:30-32

"Then I perceived that God had not sent him at all... For this reason he was hired, that I should be afraid and act that way and sin, so that they might have cause for an evil report, that they might reproach me." Nehemiah 6:12-13

"For thus says the Lord of hosts, the God of Israel: 'Do not let your prophets and your diviners who are in your midst deceive you, nor listen to your dreams which you cause to be dreamed. For they prophesy falsely to you in My name; I have not sent them, says the Lord." Jeremiah 29:8-9

"But My people would not heed My voice, and Israel would have none of Me.
So I gave them over to their own stubborn heart, to walk in their own counsels.
Oh, that My people would listen to Me, that Israel would walk in My ways!
I would soon subdue their enemies, and turn My hand against their adversaries." Psalm 81:11-14

"Cry aloud,  spare not; lift up your voice like a trumpet;
Tell My people their transgression, and the house of Jacob their sins.
Yet they seek Me daily, and delight to know My ways,
As a nation that did righteousness, and did not forsake the ordinance of their God.
They ask of Me the ordinances of justice; they take delight in approaching God.
'Why have we fasted,’ they say, ‘and You have not seen?
Why have we afflicted our souls, and You take no notice?’" Isaiah 58:1-3

"...‘therefore behold, I, even I, will utterly forget you and forsake you, and the city that I gave you and your fathers, and will cast you out of My presence. And I will bring an everlasting reproach upon you, and a perpetual shame, which shall not be forgotten.’” Jeremiah 23:39-40

"An astonishing and 'horrible thing has been committed in the land:
The prophets prophesy falsely, and the priests rule by their own power;
And My people love to have it so. But what will you do in the end?" Jeremiah 5:30-31

Restoration for those who trust and follow God

"Thus says the Lord God: 'Although I have cast them far off among the Gentiles, and although I have scattered them among the countries, yet I shall be a little sanctuary for them in the countries where they have gone....
      "I will gather you from the peoples, assemble you from the countries where you have been scattered, and I will give you the land of Israel.” ’ And they will go there, and they will take away all its detestable things and all its abominations from there.
     "Then I will give them one heart, and I will put a new spirit within them, and take the stony heart out of their flesh, and give them a heart of flesh, that they may walk in My statutes and keep My judgments and do them; and they shall be My people, and I will be their God. But as for those whose hearts follow the desire for their detestable things and their abominations, I will recompense their deeds on their own heads,” says the Lord God." Ezekiel 11:16-21

New Testament warnings

"For false christs and false prophets will rise and show signs and wonders to deceive, if possible, even the elect. But take heed; see, I have told you all things beforehand." Mark 13:22-23

"Beware lest anyone cheat you through philosophy and empty deceit, according to the tradition of men, according to the basic principles of the world, and not according to Christ. " Colossians 2:8

"Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world." 1 John 4:1

"Beware of false prophets, who come to you in sheep’s clothing, but inwardly they are ravenous wolves.  You will know them by their fruits. Do men gather grapes from thorn-bushes or figs from thistles?  Even so, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, nor can a bad tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Therefore by their fruits you will know them." Matthew 7:15-20

"For when they say, 'Peace and safety!' then 'sudden destruction comes upon them, 'as labor pains upon a pregnant woman. And they shall not escape. 'But you, brethren, are not in darkness, so that this Day should overtake you as a thief. 'You are all 'sons of light and sons of the day. We are not of the night nor of darkness. 'Therefore let us not sleep, as others do, but let us watch and be sober...  putting on the breastplate of faith and love, and as a helmet the hope of salvation." 1 Thessalonians 5:3-8

See also The Armor of God and Our Shepherd