Over a billion people claim to be Christians.
Czarist Russia was passionately Christian.
South Africa under apartheid was also Christian.
The ethnic-cleansing Bosnians were motivated by their Christian heritage.
The segregated American South certainly thought of itself as Christian.
All these groups had two things in common: the label 'Christian,' and a firm belief that they were “an,” perhaps “the,” truest expression of Christianity. Most of the people in these societies viewed other professing believers as perhaps less informed than they or, more commonly, as simply counterfeit.
Sooner or later, most groups experience a struggle in which one of its factions claim the exclusive rights to use the label. In current American politics, life-long Republicans are getting purged from their party because classical Republicanism has apparently lost its right to use a label now claimed by Libertarian nativists as their proprietary right.
The same thing occurs in Christian circles though, and often for the same reasons.
In many Evangelical publications one constantly encounters phrases like "true believers," "born again Christians," or "Bible believing Christians." The phrases are meant to make a point: that while others may label themselves "Christian," they are not to be thought of as legitimate because they don't subscribe to the tenants of those who read such publications. Since we might mistakenly think such people are Christians, we apparently need to insert adjectives like "true," bible believing," and so forth before our own use of a label that we unfortunately share with others who do things differently than we.
Of course, these adjectives imply that someone has the authority, the right or the responsibility to decide who is (or is not) entitled to use the label "Christian." They also control the flow of judgment so that judgment flows in only one direction -- toward those being judged – and never toward those who are doing the judging.
Christianity is two thousand years old. In its long history, it has taken on a myriad of cultural forms. Ethiopian Copts, for example, are among the world's oldest groups of believers. Charismatic Protestants are among some of the youngest. Each of these embody certain cultural uniquenesses, which may cause the members of both communities to ignore the common ground from which they each spring. Nowadays of course, church can borrow from both Copts and Charismatics but that will probably tick off important factions in both communities. We like our distinctions. Actually, we tend to be more committed to our distinctions than we to the underlying faith itself.
The things that really divide Christians are mostly the cultural, ethnic and linguistic adaptations that believers have made as their religion spread across the globe into new places and into new eras of time. Our faith's cultural products -- things like Gospel music or stained glass -- become enshrined and sanctified. At some point in this process, our faith becomes difficult to envision if it lacks the particular wrappings of our branch of the faith.
Theology has usually followed, rather than preceded, such differences. A group's theology usually develops to defend its cultural preferences and habits rather than the other way around.
For example, the use of incense in worship, although mentioned often in the Bible, is unacceptable to Evangelicals. Sunday School and altar calls on the other hand, (which the Bible does not mention,) are viewed as essential. Merely pointing something like that out can make people pretty angry though. The reason is simple: people's passion nearly always gets wrapped up in cultural preferences more than in the actual essence of faith.
These cultural differences were not much of a problem to believers in earlier times. Greek Orthodox people lived far away, or a long time ago. A Southern Baptist didn't have to think about who such people were or what possible kingship they might have to him. Of course, the same can be said for Christians of other groups. Christians loved the faith as they had received it. They didn't question whether or why the form in which they experienced faith differed from the form preferred by those of other times and in other places. Our grandparents meant no harm by adopting this attitude. They were merely the children of their own time and place and expressed their faith accordingly.
In our time and place, we can no longer innocently adopt such a stance. We are in a globalized world; Copts, Baptists, Pentecostals and groups called "the Fish House" and the "Watching Room," compete for the label "Christian." Some younger believers have resolved this by deciding not to use the word Christian at all. They have broken with New Testament language altogether and call themselves "Christ followers." But surely that is simply a novel way to say "real Christian." Calling themselves "Christ followers" helps these enlightened people communicate to themselves (and to the rest of the world) that they are the real McCoy and are not like all those other fake, nominal, or, God-forbid, traditional Christians.
There is nothing wrong with adapting our faith to our own time and place if these adaptations do not conflict with the underlying faith itself. That is the problem however. If our loyalties to the adaptation, the faction, the local expression of our faith gets too intense, we can actually lose the faith itself. When Bosnian Serbs practiced ethnic cleansing, Christians in other places did not accept their explanation that they were actually defending the faith. We felt like they were violating our common faith by misusing the label.
From time to time, someone must have the courage to examine the faction in the light of the whole community. Then, he or she must have the courage to confront the claim of over zealous factions that work to eradicate all nuances and expressions of their community that differ from theirs.
Democracy, by very definition, contains difference. If we eliminate the difference, we destroy the democracy. We can win elections and arguments and still sustain the democracy. But if we brutally suppress our opponents, we may lose the things that support not only them, but which also which supports us. An arm or a leg cannot live if it annihilates all the other body parts. St. Paul makes this point very clear in his first letter to the Corinthians.
Maintaining civility, trust and mutual respect with those with whom we differ but with whom we also defend common community, is difficult. It requires people to become adults. It requires not only a desire to win, but also a willingness to compromise rather than to keep pushing until all that all sides hold precious gets utterly and irretrievable lost.