What's that quote about "keep your friends close, and your enemies closer"? I think Sun-Tzu said it in the art of war, but I'd like to make an argument for a modified version of it as a definition of what church should be like. Something like, "Keep your tribe close, and other tribes even closer." Or something like that.
I know clergy in other denominations, for example, where a majority of their congregation votes all of the same persuasion. I know congregations that expect considerable uniformity of thought and confession. I even used to have breakfast with a pastor who would always ask me how I tolerate being in a church where I know clergy (as well as parishioners) think and confess quite differently from myself. He came out of a "close" communion tradition where all the clergy were trained to think via very similar and tight confessional categories.
However, I think my own practice as a Christian is like this--I have (often) strong sensibilities about what I confess and believe, but I intentionally cultivate relationships in traditions far flung from my own. I like to think I'm both strong and open at the same time. For example, I subscribe to both Sojourners and First Things, The Atlantic and The New Republic, The Lutheran Forum and The Lutheran. That illustrates the practice I'm encouraging in terms of magazine subscriptions, and as a bonus advertises some good magazines.
Similarly, in parish life, my preferred modus operandi is to be very clear about where I come from in terms of my personal faith, politics, etc., but then to create space for people of widely disparate perspectives to also have a place at the table and in the congregation with me. I probably often fail at this, and am blind to the ways my own leanings influence others are keep me closer to my tribe than to those outside my tribe, but if I do this, please tell me. The only way I can avoid is to continually learn and be reminded.
What I think is witnessed in Scripture, perhaps especially in the diversity of the early church leaders, some of whom were missionaries to the Gentiles, while others were missionaries to the Jews in Jerusalem, is a similar kind of practice. We're different, they'd say, but we're different together. Jesus himself spent time with very, very different kinds of people, the kinds of people most people, even extremely "together" people, preferred apartness from. He practice "open table commensality." We ought to do the same.
So, I consider it a mark of a healthy church and a faithful people that it can live together with considerable difference. Fusions of horizon are very difficult, we see this all the time. But if we can't live together there's simply no possibility for the Spirit to do the work of reconciliation.
Fierce humility. Maybe that's the best title for this approach. Strongly convicted in faith, but humble enough to know that all convictions are interim convictions when seen in light of the eschaton. Not hiding behind a mask of supposed impartiality. It is probably the best way to bring races, and classes, and nations, together as the one body in Christ.