1john2:19: They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us; but they went out, that they might be made manifest that they were not all of us.An AntiChrist is someone who shows up like a Christian, but he does not process the same thought from the beginning.
1john2:22 Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son. 23Whosoever denieth the Son, the same hath not the Father: (but) he that acknowledgeth the Son hath the Father also .
Spirit of AntiChrist
The Spirit of AntiChrist to deny the natures and works of Jesus Christ.
I John 4:3: Every spirit that confesseth that Jesus Christ is come in the flesh is of God: And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.
The nature of Jesus
The works of Jesus
A liar and antichrist are the same kind
Any one who teaches about GOD but denies Jesus Christ is deceiver.
II John 1:7 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.
Anyone, whatever he call himself, comes but teaches different from the
doctrine of Jesus Christ is liar and evil
I John 1:9-11 He that abideth in the doctrine of Christ, he hath both the Father and the Son. If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him Godspeed; For he that biddeth him Godspeed is partaker of his evil deeds.