1 John 2:18 (KJV) "Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time. 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."
John goes on to say:
an antichrist is one who denies that Jesus is the Christ.
an antichrist is one who denies the Father and the Son.
an antichrist is one who denies that Jesus came in the flesh and is God.
the "spirit" of antichrist is come and is already in the world deceiving Christians.
John also declares that the Antichrist will come.
It is time. Not everyone who is part of the Church organization is part of the Church organism. That is, there are people in the church that are not born-again believers in Jesus Christ. And some of them are "antichrists," false teachers that arise out of the church and lead baby or immature christians into herrisies.