1 John 4:1
Loved ones, do not believe [the message of] every spirit [i.e., every person claiming to be a teacher], but test the spirits [i.e., require proof that they and their message are genuine] to see whether they represent God [or not], because many false prophets have begun circulating throughout the world.
2 Peter 2:1
But just as there were false prophets among the people before, there will also be false teachers among you [Christians]. They will privately teach harmful doctrines that destroy people [spiritually], by even denying [that Jesus is] the Master, [and thereby] destroying themselves quickly.
1 John 2:18
Dear children, it is [now] the last hour [i.e., the final period of God's dealing with people on earth], and since you have heard that an antichrist [i.e., a person who is against Christ] is coming, even now [you should be aware that] many antichrists have [already] come. This is [one way] we know that this is the last hour.
1 Thessalonians 5:21
Put everything [i.e., speakers and their messages] to the test, [then] hold onto what is good.
Luke 12:57
"And why do you not judge for yourselves what is right?
Acts 17:11
Now these people [in Berea] had more character than those in Thessalonica because they [not only] received the message with an open mind but [also] examined the [Old Testament] Scriptures every day to see if what they had heard was really true.
1 Corinthians 12:10
Another [is given] the ability to perform miracles; and another [is given] the ability to prophesy [supernaturally]; and another [is given] the ability to speak in different languages [supernaturally]; and still another [is given] the ability to interpret those languages [supernaturally].
1 Corinthians 14:29
And [only] two or three prophets should speak [in one meeting], and [then] other people should determine the significance [of their messages].
1 Timothy 4:1
Now the Holy Spirit specifically says that in later times [Note: "Later times" in the New Testament usually refers to the period following the first coming of Christ and the establishment of the church], some people will fall away from the faith [i.e., the true teaching of Christianity]. They will pay attention to deceitful spirits [i.e., lying people] and the teaching of evil spirits.
2 John 1:7
For many deceivers have begun circulating in the world; they are those who do not confess that Jesus Christ has come [to earth] in a physical body. Such a person is the deceiver and the antichrist [See I John 2:18f].
Revelation 2:2
I know about your deeds, your hard work and your perseverance. [I know] that you cannot tolerate wicked men and that you have tested those who call themselves apostles, but really are not, and found them to be liars.
Matthew 7:15-16
"Look out for deceiving prophets, who approach you wearing sheep's clothing, but who are [actually] starving wolves in their hearts.
Matthew 24:4-5
And Jesus answered them, "Pay attention so that no one leads you astray [from the truth].
Matthew 24:23-26
Then if anyone says to you, 'Look, here is Christ,' or 'There [he is],' do not believe him.
Mark 13:21
And then if anyone says to you, 'Look, here is Christ,' or 'Look, there He is,' do not believe him.
Luke 21:8
And He replied, "Pay attention, so that you are not led astray [from the truth]. For many [false teachers] will come, claiming to be me, and saying, 'I am [the Christ],' and 'The time is near.' [But] do not go after them.
Acts 20:29
[Because] I know that after I am gone [from here] there will be vicious wolves [i.e., ravaging false teachers] who will come in among you, and they will not spare the flock [i.e., the congregation].
Romans 16:18-19
For such men are not serving our Lord Christ but their own [unspiritual] appetites. They are deceiving the minds of innocent people by their smooth talk and flattering words.
2 Timothy 3:13
But evil people and impostors will go from bad to worse [in their behavior], deceiving people and being deceived by them.