Deuteronomy 13:1-3

13:1 Suppose a prophet or one who foretells by dreams should appear among you and show you a sign or wonder, 13:2 and the sign or wonder should come to pass concerning what he said to you, namely, “Let us follow other gods” – gods whom you have not previously known – “and let us serve them.” 13:3 You must not listen to the words of that prophet or dreamer, for the Lord your God will be testing you to see if you love him with all your mind and being.

Matthew 24:5

24:5 For many will come in my name, saying, ‘I am the Christ,’ and they will mislead many.

Matthew 24:23-25

24:23 Then if anyone says to you, ‘Look, here is the Christ!’ or ‘There he is!’ do not believe him. 24:24 For false messiahs and false prophets will appear and perform great signs and wonders to deceive, if possible, even the elect. 24:25 Remember, I have told you ahead of time.

Luke 17:23-24

17:23 Then people will say to you, ‘Look, there he is!’ or ‘Look, here he is!’ Do not go out or chase after them. 17:24 For just like the lightning flashes and lights up the sky from one side to the other, so will the Son of Man be in his day.

Luke 21:8

21:8 He said, “Watch out that you are not misled. For many will come in my name, saying, ‘I am he,’ and, ‘The time is near.’ Do not follow them!

John 5:43

5:43 I have come in my Father’s name, and you do not accept me. If someone else comes in his own name, you will accept him.