You can and should test the spirits

“Beloved, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.” (1 John 4:1 NASB)

There are deceiving spirits

“The Spirit clearly says that in later times some will abandon the faith and follow deceiving spirits and things taught by demons.” (1 Tim. 4:1 NIV)

There are false prophets and teachers among you

“Now there were also false prophets among the people, just as there will be false teachers among you. They will secretly introduce destructive heresies that even deny the Master who bought them, bringing swift destruction on themselves.” (2 Peter 2:1 NASB)

You can be lied to so be very careful!

“He said to him, "I also am a prophet like you, and an angel spoke to me by the word of the LORD, saying, 'Bring him back with you to your house, that he may eat bread and drink water.'" But he lied to him.” (2 Kings 13:18 NASB)

Some only speak a vision of their own imagination

“Thus says the LORD of hosts, "Do not listen to the words of the prophets who are prophesying to you. They are leading you into futility; They speak a vision of their own imagination, Not from the mouth of the LORD.” (Jer. 23:16 NASB)

“Knowing this first of all, that no prophecy of Scripture comes from someone's own interpretation.” (2 Peter 1:20 ESV)

“For thus says the LORD of hosts, the God of Israel, 'Do not let your prophets who are in your midst and your diviners deceive you, and do not listen to the dreams which they dream.” (Jer. 29:8 NASB)

They are wolves in sheep’s clothing

“Beware of false prophets. They come to you in sheep's clothing, but inwardly they are ravenous wolves.” (Matt. 7:15 NASB)

Don’t be a simpleton

“Only simpletons believe everything they're told! The prudent carefully consider their steps.” (Prov. 14:15 NLT)

Examine the Scriptures carefully to see if things are so

Now these Jews were more noble than those in Thessalonica; they received the word with all eagerness, examining the Scriptures daily to see if these things were so.” (Acts 17 11 ESV)

“But examine everything carefully; hold fast to that which is good.” (1 Thes. 5:21 NASB)

“All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness.” (2 Tim. 3:16 ESV)