1 John 4:1

Dearly beloved, stop believing every so-called spiritual utterance, but keep testing them to see whether they come from God, because many false prophets have gone out into the world.

2 Peter 2:1

Now there were false prophets among the people, just as there will be false teachers among you too, who will insidiously introduce destructive heresies and deny the Master who has bought them, thus bringing on themselves swift destruction.

1 John 2:18

Little children, it is the last hour, just as you have heard that Antichrist is Coming, and already many Antichrists have appeared; so we may be sure that it is the last hour.

1 Thessalonians 5:21

but continue to prove all things until you can approve them, and then hold on to what is good.

Luke 12:57

Why do you not of yourselves decide what is right?

Acts 17:11

The Jews there were better disposed than those in Thessalonica, for they welcomed the message with all eagerness and carried on a daily study of the Scriptures to see if Paul's message was true.

1 Corinthians 12:10

to another, power for working wonders; to another, prophetic insight; to another, the power to discriminate between the true Spirit and false spirits; to another, various ecstatic utterances; and to another, the power to explain them.

1 Corinthians 14:29

Let two or three prophets speak, and the rest consider carefully what is said;

1 Timothy 4:1

Now the Spirit distinctly declares that in later times some will turn away from the faith, because they continuously give their attention to deceiving spirits and the things that demons teach

2 John 1:7

For many impostors have gone out into the world, men who do not own that Jesus Christ continues to come in human form. A person like this is the impostor and the Antichrist.

Revelation 2:2

"I know what you have done; your hard work and patient endurance; that you cannot tolerate wicked persons; that you have tested those who claimed to be apostles although they were not, and have found them to be imposters,

Matthew 7:15-16

"Look out for false prophets, who come to you under the guise of sheep, but inside they are devouring wolves.

Matthew 24:4-5

Jesus answered, "Look out that no one misleads you about it,

Matthew 24:23-26

"If anyone at that time says to you, 'Here is the Christ!' or 'There He is!' do not believe it,

Mark 13:21

"If anyone says to you at that time, 'Look! Here is the Christ,' or, 'Look! There He is,' do not believe it.

Luke 21:8

So He said, "You must take care not to be misled about it! For many will come bearing the name of Messiah, and saying, 'I am He,' and, 'The time is near.' Do not go after them.

Acts 20:29

Because I know that after I have gone violent wolves will break in among you and will not spare the flock.

Romans 16:18-19

For such men are really not serving our Lord Christ but their own base appetites, and by their fair and flattering talk they are deceiving the hearts of unsuspecting people.

2 Timothy 3:13

But bad men and imposters will go on from bad to worse, misleading others and misled themselves.

Treasury of Scripture Knowledge

Summary

Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world.

Bible References

Believe not

Matthew 7:15
"Look out for false prophets, who come to you under the guise of sheep, but inside they are devouring wolves.
Matthew 24:4
Jesus answered, "Look out that no one misleads you about it,
Romans 16:18
For such men are really not serving our Lord Christ but their own base appetites, and by their fair and flattering talk they are deceiving the hearts of unsuspecting people.
2 Peter 2:1
Now there were false prophets among the people, just as there will be false teachers among you too, who will insidiously introduce destructive heresies and deny the Master who has bought them, thus bringing on themselves swift destruction.

Try

Luke 12:57
Why do you not of yourselves decide what is right?
Acts 17:11
The Jews there were better disposed than those in Thessalonica, for they welcomed the message with all eagerness and carried on a daily study of the Scriptures to see if Paul's message was true.
Romans 16:19
Yes, your obedience has been told to everybody; so I am delighted about you, but I want you to be wise about what is good and innocent about what is bad.
1 Corinthians 14:29
Let two or three prophets speak, and the rest consider carefully what is said;
1 Thessalonians 5:21
but continue to prove all things until you can approve them, and then hold on to what is good.
Revelation 2:2
"I know what you have done; your hard work and patient endurance; that you cannot tolerate wicked persons; that you have tested those who claimed to be apostles although they were not, and have found them to be imposters,

General references

Matthew 24:11
Many false prophets will appear and mislead many people;
John 8:47
Whoever is sprung from God listens to what God says. This is why you do not listen to me: you are not sprung from God."
1 Corinthians 14:32
for the spirits of prophets yield to prophets;