2 John 1:7

for many deceivers are entered into the world, who do not confess Jesus Christ did come in the flesh. This is the deceiver, and the antichrist.

1 John 4:1-3

Beloved, do not believe every spirit, but try the spirits, whether they be from God; because many false prophets are gone forth into the world.

1 John 2:26

These things I have written to you, concerning them who deceive you;

2 Peter 2:1-3

But there were also false prophets among the people, even as there will be false teachers among you; who will privately introduce destructive sects, denying even the Lord who bought them, bringing on themselves swift destruction.

1 John 2:18-22

Young children, it is the last period. And as you have heard that the antichrist comes, so, now, there are many antichrists; whence you know that it is the last period.

Revelation 12:9

And thus the great dragon was cast out; even the old serpent called the Devil, and Satan, who deceives the world, was cast out to the earth; and his angels were cast out with him.

Revelation 13:14

and it deceives the inhabitants of the earth by signs which it is given it to do before the beast; commanding the inhabitants of the earth to make an image of the beast that had the wound of the sword, and lived.

Treasury of Scripture Knowledge

Summary

For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist.

Bible References

Many

2 Peter 2:1
But there were also false prophets among the people, even as there will be false teachers among you; who will privately introduce destructive sects, denying even the Lord who bought them, bringing on themselves swift destruction.
1 John 2:18
Young children, it is the last period. And as you have heard that the antichrist comes, so, now, there are many antichrists; whence you know that it is the last period.
1 John 4:1
Beloved, do not believe every spirit, but try the spirits, whether they be from God; because many false prophets are gone forth into the world.

Who

1 John 4:2
By this you know the Spirit of God: Every spirit that confesses Jesus Christ has come in the flesh, is from God.
Revelation 12:9
And thus the great dragon was cast out; even the old serpent called the Devil, and Satan, who deceives the world, was cast out to the earth; and his angels were cast out with him.
Revelation 13:14
and it deceives the inhabitants of the earth by signs which it is given it to do before the beast; commanding the inhabitants of the earth to make an image of the beast that had the wound of the sword, and lived.

This is

1 John 2:22
Who is a liar, if not he who denies that Jesus is the Christ? He is the antichrist who denies the Father and the Son.
1 John 4:3
And every spirit that does not confess Jesus, is not from God: and this is that spirit of antichrist, which you have heard that it comes, and now is in the world already.