Deuteronomy 18:21

Now you may ask yourselves, "How will we be able to discern that the LORD has not spoken?'

1 Thessalonians 5:24

The one who calls you is faithful, and he will continue to be faithful.

1 John 4:1-3

Dear friends, stop believing every spirit. Instead, test the spirits to see whether they are from God, because many false prophets have gone out into the world.

Revelation 2:2

"I know what you've been doing, your toil, and your endurance. I also know that you cannot tolerate evil people. You have tested those who call themselves apostles, but are not, and have found them to be false.

Treasury of Scripture Knowledge

Summary

And if thou say in thine heart, How shall we know the word which the LORD hath not spoken?

Bible References

General references

1 Thessalonians 5:24
The one who calls you is faithful, and he will continue to be faithful.
1 John 4:1
Dear friends, stop believing every spirit. Instead, test the spirits to see whether they are from God, because many false prophets have gone out into the world.
Revelation 2:2
"I know what you've been doing, your toil, and your endurance. I also know that you cannot tolerate evil people. You have tested those who call themselves apostles, but are not, and have found them to be false.

International Standard Version Copyright © 1996-2008 by the ISV Foundation.