Deuteronomy 18:21

And when thou sayest in thy heart, How do we know the word which Jehovah hath not spoken? --

1 Thessalonians 5:24

stedfast is He who is calling you, who also will do it.

1 John 4:1-3

Beloved, every spirit believe not, but prove the spirits, if of God they are, because many false prophets have gone forth to the world;

Revelation 2:2

I have known thy works, and thy labour, and thy endurance, and that thou art not able to bear evil ones, and that thou hast tried those saying themselves to be apostles and are not, and hast found them liars,

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
stedfast is He who is calling you, who also will do it.
1 John 4:1
Beloved, every spirit believe not, but prove the spirits, if of God they are, because many false prophets have gone forth to the world;
Revelation 2:2
I have known thy works, and thy labour, and thy endurance, and that thou art not able to bear evil ones, and that thou hast tried those saying themselves to be apostles and are not, and hast found them liars,