1 John 4:1

Beloved, believe not every spirit, but prove the spirits, if they are of God; because many false prophets are gone out into the world.

2 Peter 2:1

But there were false prophets also among the people, as there shall be also among you false teachers, who shall bring in by the bye destructive heresies, and deny the master that bought them, bringing upon themselves swift destruction;

1 John 2:18

Little children, it is the last hour, and, according as ye have heard that antichrist comes, even now there have come many antichrists, whence we know that it is the last hour.

1 Thessalonians 5:21

but prove all things, hold fast the right;

Luke 12:57

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

Acts 17:11

And these were more noble than those in Thessalonica, receiving the word with all readiness of mind, daily searching the scriptures if these things were so.

1 Corinthians 12:10

and to another operations of miracles; and to another prophecy; and to another discerning of spirits; and to a different one kinds of tongues; and to another interpretation of tongues.

1 Corinthians 14:29

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

1 Timothy 4:1

But the Spirit speaks expressly, that in latter times some shall apostatise from the faith, giving their mind to deceiving spirits and teachings of demons

2 John 1:7

For many deceivers have gone out into the world, they who do not confess Jesus Christ coming in flesh this is the deceiver and the antichrist.

Revelation 2:2

I know thy works and thy labour, and thine endurance, and that thou canst not bear evil men; and thou hast tried them who say that themselves are apostles and are not, and hast found them liars;

Deuteronomy 13:1-5

If there arise among you a prophet, or one that dreameth dreams, and he give thee a sign or a wonder,

Proverbs 14:15

The simple believeth every word; but the prudent man heedeth his going.

Jeremiah 5:31

the prophets prophesy falsehood, and the priests rule by their means; and my people love to have it so. But what will ye do in the end thereof?

Jeremiah 29:8-9

For thus saith Jehovah of hosts, the God of Israel: Let not your prophets that are in your midst, nor your diviners deceive you, neither hearken to your dreams, which ye like to dream.

Matthew 7:15-16

But beware of false prophets, which come to you in sheep's clothing, but within are ravening wolves.

Matthew 24:4-5

And Jesus answering said to them, See that no one mislead you.

Matthew 24:23-26

Then if any one say to you, Behold, here is the Christ, or here, believe it not.

Mark 13:21

And then if any one say to you, Lo, here is the Christ, or Lo, there, believe it not.

Luke 21:8

And he said, See that ye be not led astray, for many shall come in my name, saying, I am he, and the time is drawn nigh: go ye not therefore after them.

Acts 20:29

For I know this, that there will come in amongst you after my departure grievous wolves, not sparing the flock;

Romans 16:18-19

For such serve not our Lord Christ, but their own belly, and by good words and fair speeches deceive the hearts of the unsuspecting.

2 Timothy 3:13

But wicked men and juggling impostors shall advance in evil, leading and being led astray.

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

Deuteronomy 13:1
If there arise among you a prophet, or one that dreameth dreams, and he give thee a sign or a wonder,
Proverbs 14:15
The simple believeth every word; but the prudent man heedeth his going.
Jeremiah 5:31
the prophets prophesy falsehood, and the priests rule by their means; and my people love to have it so. But what will ye do in the end thereof?
Jeremiah 29:8
For thus saith Jehovah of hosts, the God of Israel: Let not your prophets that are in your midst, nor your diviners deceive you, neither hearken to your dreams, which ye like to dream.
Matthew 7:15
But beware of false prophets, which come to you in sheep's clothing, but within are ravening wolves.
Matthew 24:4
And Jesus answering said to them, See that no one mislead you.
Romans 16:18
For such serve not our Lord Christ, but their own belly, and by good words and fair speeches deceive the hearts of the unsuspecting.
2 Peter 2:1
But there were false prophets also among the people, as there shall be also among you false teachers, who shall bring in by the bye destructive heresies, and deny the master that bought them, bringing upon themselves swift destruction;

Try

Luke 12:57
And why even of yourselves judge ye not what is right?
Acts 17:11
And these were more noble than those in Thessalonica, receiving the word with all readiness of mind, daily searching the scriptures if these things were so.
Romans 16:19
For your obedience has reached to all. I rejoice therefore as it regards you; but I wish you to be wise as to that which is good, and simple as to evil.
1 Corinthians 14:29
And let two or three prophets speak, and let the others judge.
1 Thessalonians 5:21
but prove all things, hold fast the right;
Revelation 2:2
I know thy works and thy labour, and thine endurance, and that thou canst not bear evil men; and thou hast tried them who say that themselves are apostles and are not, and hast found them liars;

General references

Deuteronomy 18:21
And if thou say in thy heart, How shall we know the word that Jehovah hath not spoken?
Proverbs 19:27
Cease, my son, to hear the instruction which causeth to stray from the words of knowledge.
Matthew 24:11
and many false prophets shall arise and shall mislead many;
John 8:47
He that is of God hears the words of God: therefore ye hear them not, because ye are not of God.
1 Corinthians 14:32
And spirits of prophets are subject to prophets.