The antichrist that John expects to come are those who pretend to be part of God's true church, but as John writes in verse 19'"they went out of from us but they were not of us.
The antichrist are deceives who have gone out into the world who do not confess Christ Jesus as coming in the flesh . This is a deceiver and an antichrist. 2 John 7. Antichrist are those who are against the true Christ
Teaching and preaching of another Gosple is the spirit operating now