Q4: What exactly do you think is the major difference between the Galatian and the Corinthian churches that caused Paul to write to them differently?
A4: I think the standard answer is — the one you may have heard on the White Horse Inn, for example — is that the Galatians were practically not a church and the Corinthians were a church. That is: the Galatians were practically denying the Gospel, and the Corinthians were only ignoring it.
For the sake of this exchange, I’m willing to utterly accept that interpretation of Paul’s approach and intent in the two different letters.
What we cannot do with that distinction is then say, “and what Paul meant for the Galatians is that the good ones (if there were any) had to leave the bad ones for the sake of their own personal/ecclesiastical holiness.” You cannot find anything in that letter which says that, implies that, or can be twisted to say such a thing. What is utterly vacant from the letter to the Galatians is the command to leave, or any instructions on how to leave.
See: some will say that Paul offers the Galatians a terse and cold salutation. But those people simply don’t bother to compare Gal 1:1-5 to 1 Cor 1:1-2, or Col 1:1-2. The salutation of Gal 1 is actually longer and more robust theologically than it is in Col 1 — and yet it still extends the same qualifiers for those to whom it is written: the saints. He calls them “the saints and the faithful (ones)” in writing to the Colossians; he says to the Galatians that Christ died for “us” (meaning: you and me; all of us).
That said, the tone of Galatians is plainly one of discipline, as is the tone of 1 Cor. Paul is exhorting them against their failings because they are serious. And his fear is that they are turning away from the Gospel.
But the first obvious item is that Paul doesn’t write them a letter to tell them he’s finished with them. That is: Paul doesn’t separate from the foolish Galatians! Unlike your interpretation which says Paul isn’t writing to the bad ones, plainly Paul addresses the foolish Galatians (Gal 3:1) with his rebuke.
The last obvious item (because of the limits of the word count) is Gal 6:1-5, where Paul says exactly what to do with a person in the church who is in grave error. Your method and defintion [sic] of separation utterly ignores that. I pray for your own sake you can be rid of your mistake and find a place for Paul’s full teaching to the Galatians in your theology.