I think the “no true Scotsman” thing comes from the fact that every denomination seems to define itself apart from the others, (the individualistic mentality gone crazy in my opinion). It’s not up to me to judge who’s a Christian and who’s not. However our own scriptures tell us “You will know them by their fruit.” Matthew 7:16
If not every denomination, many of them seem to call themselves “the true” one, or the only one. Maybe I’m missing something, but I can’t see how that attitude honors Christ. As for myself, I’m not a member of any church, although I’m more active in the one I attend than most members are.
The Protestant movement was born out of protest, and although the goal may have been a worthy one, I think that the spirit continues today every time I see a church split, or yet another denomination. When I sat down and thought about how it works, I concluded I’m not at all comfortable with that label, yet I’m not a Catholic either. Too many generations removed to even think of going there.
When Paul wrote to the churches, he wrote to the church (all the believers) in a geographical area. Hence you have “the church of Ephesus, the church of Rome, the church of Corinth, and so on. Yet so many of us persist in defining ourselves as elite members of separate and distinct denominations (“God loves US best!”) rather than the body of Christ in a geographical area that we were meant to be. He was not writing to the Baptists, the Catholics, or the Episcopalians (even if it is called The Church of England). :)
I’d better stop here. This is long enough.