1 John 1:10-11: He was in the world, and the world was made by him, and the world knew him not. He came to His own, and His own did not receive Him. That's 2 John. And yes, the bible makes clear that Christians are supposed to live among Christians and only associate with Christians. We are to reject the world of satanic Jews and Jews themselves. Thus the, "love thy neighbor." Which really means, "love your fellow Christians." I find most Christians don't read the bible, read the bible and don't understand, they only listen to others and ministers talk about it, read the wrong bible, or their church is corrupt, using a corrupt bible. The bible was created to keep us safe from Jews and the other children of the devil. The problem is, as you rightly point out, most Christians are in name only. A cross has become decoration and the label, "Christian", is simply a form of virtue signaling to imply they are better than others.