[xzins]

We can always argue who really is a believer in Jesus. However, whoever that might be, the requirement for unity is upon them by virtue of Jesus’ own instructions.

Just for me, I kind of doubt those groups that think Christianity somehow devolved to their own small group found in America. It strikes me as uniquely odd that these people will read about, for example, “Corinthians” and somehow ignore that that particular location is far away in another corner of the earth. In their minds, all those believers in those biblical locations wandered across the earth until landing in, for example, Kentucky. And that is why all of Christianity eventually came to reside in Kentucky and even expand out to Tennessee.

[Resettozero]

...those groups...their own small group...In their minds...those believers...

And that is why all of Christianity eventually came to reside in Kentucky and even expand out to Tennessee.

Well, yeah!

After all, the local church is...local.

The Church of Jesus Christ is all believers everywhere throughout this age, alive or asleep in Christ, who have been given to Him by the Father in Heaven.

(But it is not clear from your post if you're referring to just wayward backwoods cults that are not in fact Christian.)

[Elsie]

Yes; we humans do think the world revolves around us!