1 John 4:1

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

2 Peter 2:1

But there arose false prophets also among the people, as among you also there will be false teachers, who, indeed, will stealthily bring in destructive heresies, denying even the Master Who bought them, bringing upon themselves swift destruction:

1 John 2:18

Little children, it is the last hour; and, as ye heard that Anti-Christ is coming, even now many anti-christs have arisen; whence we know that it is the last hour.

1 Thessalonians 5:21

but prove all things, hold fast that which is good.

Luke 12:57

And why even of yourselves do ye not judge what is right?

Acts 17:11

And these were more noble than those in Thessalonica, in that they received the word with all readiness of mind, examining the Scriptures daily, whether these things were so.

1 Corinthians 12:10

and to another, workings of mighty deeds; and to another, prophecy; and to another, discerning of spirits; to another, various kinds of tongues; and to another, interpretation of tongues.

1 Corinthians 14:29

And let the prophets, two or three, speak, and the others judge.

1 Timothy 4:1

But the Spirit expressly saith, that in later times, some will fall away from the faith, giving heed to seducing spirits, and to teachings of demons,

2 John 1:7

Because many deceivers went out into the world, who confess not Jesus Christ as coming in flesh. This is the deceiver and the Anti-Christ.

Revelation 2:2

"I know your works and your toil, and your patience, and that you cannot bear evil men; and you tried those who call themselves apostles, and are not, and found them false;

Revelation 2:2-5

"I know your works and your toil, and your patience, and that you cannot bear evil men; and you tried those who call themselves apostles, and are not, and found them false;

Revelation 2:2

"I know your works and your toil, and your patience, and that you cannot bear evil men; and you tried those who call themselves apostles, and are not, and found them false;

Revelation 2:2

"I know your works and your toil, and your patience, and that you cannot bear evil men; and you tried those who call themselves apostles, and are not, and found them false;

Revelation 2:2-9

"I know your works and your toil, and your patience, and that you cannot bear evil men; and you tried those who call themselves apostles, and are not, and found them false;

Matthew 7:15-16

"Beware of false prophets, who, indeed, come to you in sheep's clothing, but within are ravening wolves.

Matthew 24:4-5

And Jesus, answering, said to them, "Take heed that no one lead you astray;

Matthew 24:23-26

Then, if any one shall say to you, 'Behold, here is the Christ!' or 'Here,' believe it not;

Mark 13:21

And then, if any one shall say to you, 'Lo, here is the Christ!' or, 'Lo, there!' believe him not;

Luke 21:8

And He said, "Take heed that ye be not led astray; for many will come in My name, saying, 'I am He,' and, 'The season has drawn near!' Go not after them.

Acts 20:29

I know that, after my departure, grievous wolves will enter in among you, not sparing the flock;

Romans 16:18-19

For those who are such are not serving our Lord Christ, but their own belly; and, through their kind words and flattering speeches, they beguile the hearts of the simple.

2 Timothy 3:13

But evil men and imposters will grow worse and worse, deceiving and being deceived.

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
"Beware of false prophets, who, indeed, come to you in sheep's clothing, but within are ravening wolves.
Matthew 24:4
And Jesus, answering, said to them, "Take heed that no one lead you astray;
Romans 16:18
For those who are such are not serving our Lord Christ, but their own belly; and, through their kind words and flattering speeches, they beguile the hearts of the simple.
2 Peter 2:1
But there arose false prophets also among the people, as among you also there will be false teachers, who, indeed, will stealthily bring in destructive heresies, denying even the Master Who bought them, bringing upon themselves swift destruction:

Try

Luke 12:57
And why even of yourselves do ye not judge what is right?
Acts 17:11
And these were more noble than those in Thessalonica, in that they received the word with all readiness of mind, examining the Scriptures daily, whether these things were so.
Romans 16:19
For your obedience reached unto all. I rejoice, therefore, over you; but I wish you to be wise as to that which is good, but simple as to evil.
1 Corinthians 14:29
And let the prophets, two or three, speak, and the others judge.
1 Thessalonians 5:21
but prove all things, hold fast that which is good.
Revelation 2:2
"I know your works and your toil, and your patience, and that you cannot bear evil men; and you tried those who call themselves apostles, and are not, and found them false;

General references

Matthew 24:11
and many false prophets will arise, and will lead many astray;
John 8:47
He that is of God hears the words of God; on this account, ye hear them not, because ye are not of God."
1 Corinthians 14:32
And spirits of prophets are subject to prophets;