1 Corinthians 5:11 is the primary basis or I should say it starts there. In this chapter the congregation in Corinth is being counseled to not associate with a man that is engaging in incest. This text also includes various other sins there in vs. 11 to show that you would not want to actively associate with those practicing these things.
Two letters in this scripture are the undoing of the organization for starters..."IS". So this scripture would only apply if the person "IS" practicing these things. Again the account here this man was belligerent. Essentially Paul is saying what the heck are you guys doing this guy is bad news.
Less would have issue with this doctrine if the scriptures were followed as prescribed here. See in that time there were no special blue envelops headed to a headquarters somewhere. When the congregation saw such behavior they were to limit their contact. Quit hanging out and so on. Essentially quit acting like there's no issue going a long as they always had with this person.
The kicker here is that as described by others 2 John 1:10 has been lumped in with this however there's little if any basis for doing this. In 2 John this was about those that were denying that Christ ever came. The Jews had preached about the Messiah coming for years now that he was there some were saying he really wasn't who he said he was. It was as simple as that. They denied that he physically came in the flesh.
This was a problem obvious as Jesus was changing things and if these folks didn't believe he was real then they obviously wouldn't follow his teachings.
I would say there are very very few "AntiChrists" that are disfellowshipped. Most are for fornication. In no way someone that commits this sort of sin is the AntiChrist.
Knowing this why in the world would the organization make this large stretch?
It's simple really...silence. It is important to silence ANYONE that brings constructive criticism. This criticism is postured as "poison", "deception" and "apostate lies".
What is is really though? Often nothing more than past doctrines that have been completely abandoned with little or in most cases NO explanation.
Hence this information from their own literature is so damning that they most go beyond the scriptures and letting the local congregation handling the matter to weaponization. An acute cutting off to silence you from speaking the truth.
