1 Corinthians 12:3
Therefore, I am telling you that no one who speaks under the influence of the Holy Spirit of God says, "Jesus is cursed!" And no one can say, "Jesus is Lord," except under the influence of the Holy Spirit.
1 John 4:1-3
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.
Revelation 16:13-14
And I saw three evil spirits that looked like frogs; [one was] coming out of the mouth of the dragon, [one] out of the mouth of the beast, and [one] out of the mouth of the false prophet.