Deuteronomy 18:20-22
20 But the prophet who presumes to speak a word in my name that I have not commanded him to speak, or who speaks in the name of other gods, that same prophet shall die.' 21 And if you say in your heart, 'How may we know the word that the Lord has not spoken?'— 22 when a prophet speaks in the name of the Lord, if the word does not come to pass or come true, that is a word that the Lord has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him.
Matthew 7:15
15 "Beware of false prophets, who come to you in sheep's clothing but inwardly are ravenous wolves.
Matthew 15:13-14
13 He answered, "Every plant that my heavenly Father has not planted will be rooted up. 14 Let them alone; they are blind guides. And if the blind lead the blind, both will fall into a pit."
John 8:12
12 Again Jesus spoke to them, saying, "I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life."