Luke 21:8

He said, “Be careful and see to it that you are not misled; for many will come in My name [appropriating for themselves the name Messiah which belongs to Me alone], saying, ‘I am He,’ and, ‘The time is near!’ Do not follow them.

Jeremiah 29:8

For thus says the Lord of hosts, the God of Israel, ‘Do not let your [false] prophets who are among you and your diviners deceive you; pay no attention and attach no significance to the dreams which they dream or to yours,

Matthew 3:2

Repent [change your inner self—your old way of thinking, regret past sins, live your life in a way that proves repentance; seek God’s purpose for your life], for the kingdom of heaven is at hand.”

Matthew 4:17

From that time Jesus began to preach and say, Repent [change your inner self—your old way of thinking, regret past sins, live your life in a way that proves repentance; seek God’s purpose for your life], for the kingdom of heaven is at hand.”

Ephesians 5:6

Let no one deceive you with empty arguments [that encourage you to sin], for because of these things the wrath of God comes upon the sons of disobedience [those who habitually sin].

2 Thessalonians 2:3

Let no one in any way deceive or entrap you, for that day will not come unless the apostasy comes first [that is, the great rebellion, the abandonment of the faith by professed Christians], and the man of lawlessness is revealed, the son of destruction [the Antichrist, the one who is destined to be destroyed],

Matthew 24:4-5

Jesus answered, “Be careful that no one misleads you [deceiving you and leading you into error].

Matthew 24:11

Many false prophets will appear and mislead many.

Matthew 24:23-25

Then if anyone says to you [during the great tribulation], ‘Look! Here is the Christ,’ or ‘There He is,’ do not believe it.

Mark 13:5-6

Jesus began to say to them, “Be careful and see to it that no one misleads you.

Mark 13:21-23

Then if anyone says to you, ‘Look, here is the Christ (the Messiah, the Anointed)!’ or, ‘Look, He is there!’ do not believe it;

Luke 17:23

They will say to you, ‘Look [the Messiah is] there!’ or ‘Look [He is] here!’ Do not go away [to see Him], and do not run after them.

John 5:43

I have come in My Father’s name and with His power, and you do not receive Me [because your minds are closed]; but if another comes in his own name and with no authority or power except his own, you will receive him and give your approval to an imposter.

John 8:24

That is why I told you that you will die [unforgiven and condemned] in your sins; for if you do not believe that I am the One [I claim to be], you will die in your sins.”

Acts 5:36-37

For some time ago Theudas rose up, claiming to be somebody [of importance], and a group of about four hundred men allied themselves with him. But he was killed, and all who followed him were scattered and came to nothing.

Acts 8:9-10

Now there was a man named Simon, who previously practiced magic in the city and amazed the people of Samaria, claiming to be someone great.

2 Corinthians 11:13-15

For such men are counterfeit apostles, deceitful workers, masquerading as apostles of Christ.

2 Thessalonians 2:9-11

The coming of the [Antichrist, the lawless] one is through the activity of Satan, [attended] with great power [all kinds of counterfeit miracles] and [deceptive] signs and false wonders [all of them lies],

2 Timothy 3:13

But evil men and impostors will go on from bad to worse, deceiving and being deceived.

1 John 4:1

Beloved, do not believe every spirit [speaking through a self-proclaimed prophet]; instead test the spirits to see whether they are from God, because many false prophets and teachers have gone out into the world.

2 John 1:7

For many deceivers [heretics, posing as Christians] have gone out into the world, those who do not acknowledge and confess the coming of Jesus Christ in the flesh (bodily form). This [person, the kind who does this] is the deceiver and the antichrist [that is, the antagonist of Christ].

Revelation 1:3

Blessed (happy, prosperous, to be admired) is he who reads and those who hear the words of the prophecy, and who keep the things which are written in it [heeding them and taking them to heart]; for the time [of fulfillment] is near.

Revelation 12:9

And the great dragon was thrown down, the age-old serpent who is called the devil and Satan, he who continually deceives and seduces the entire inhabited world; he was thrown down to the earth, and his angels were thrown down with him.

Treasury of Scripture Knowledge

Summary

And he said, Take heed that ye be not deceived: for many shall come in my name, saying, I am Christ; and the time draweth near: go ye not therefore after them.

General references

Bible References

For

John 5:43
I have come in My Father’s name and with His power, and you do not receive Me [because your minds are closed]; but if another comes in his own name and with no authority or power except his own, you will receive him and give your approval to an imposter.
Acts 5:36
For some time ago Theudas rose up, claiming to be somebody [of importance], and a group of about four hundred men allied themselves with him. But he was killed, and all who followed him were scattered and came to nothing.
Acts 8:9
Now there was a man named Simon, who previously practiced magic in the city and amazed the people of Samaria, claiming to be someone great.

And the time

Matthew 3:2
Repent [change your inner self—your old way of thinking, regret past sins, live your life in a way that proves repentance; seek God’s purpose for your life], for the kingdom of heaven is at hand.”
Matthew 4:17
From that time Jesus began to preach and say, Repent [change your inner self—your old way of thinking, regret past sins, live your life in a way that proves repentance; seek God’s purpose for your life], for the kingdom of heaven is at hand.”
Revelation 1:3
Blessed (happy, prosperous, to be admired) is he who reads and those who hear the words of the prophecy, and who keep the things which are written in it [heeding them and taking them to heart]; for the time [of fulfillment] is near.

General references

Matthew 24:23
Then if anyone says to you [during the great tribulation], ‘Look! Here is the Christ,’ or ‘There He is,’ do not believe it.
Mark 13:21
Then if anyone says to you, ‘Look, here is the Christ (the Messiah, the Anointed)!’ or, ‘Look, He is there!’ do not believe it;
Luke 17:23
They will say to you, ‘Look [the Messiah is] there!’ or ‘Look [He is] here!’ Do not go away [to see Him], and do not run after them.