In pointing toward the desired unity of the church, we must not fall into the idea that our differences have to be muted or neutered into something in which we’re all uniform. Even in the Roman Catholic tradition there is some great variety in the different orders: Franciscan, Benedictine, Dominican, etc. And for all the criticism Protestants receive for their divisions, some of it surely just, there is some wonderful variety: Quakers, Pentecostals, Methodists, etc.
In Paul’s letter to the Corinthians, he makes it clear that though the Body of Christ is one, it is made up of many parts. But to be a full body each of the parts with all of their differences need to be in place (1 Corinthians 12). Something similar should be said, I think, for the institutional church, or if you prefer, the local church/parish and churches at large. We want to work toward the complete unity Christ was praying for. We don’t in the process want to lose the rich diversity, but somehow bring all of it together into a melodious harmony.
This doesn’t mean that just anything goes. And yet within a certain framework there can be an openness to fresh movings of the Spirit in living out and being a witness to the gospel. All of that does need to be sufficiently grounded in scripture and tradition with good reasoning and a testing of the spirits as in experience, following.
In fact this unity does not only preclude divesity, but welcomes and embraces it. And in fact is committed to it. The different cultural expressions of the faith come into play here, the various ethnicities and their expression of the faith among the many gifts that Christ gives to the church. And at its heart gives witness to the full reconciliation the gospel brings to those who in normal life are divided. The Spirit’s work in the church is not about making us comfortable. We worship and are a part of one body that in the big picture is as large and diverse as the world.
The gospel is central as given in the word, the sacraments, fellowship, and care for each other, all spilling out into a witness into the world first in terms of the microcsosm of God’s grace and kingdom come in Jesus seen in the church, and in terms of the life that is lived out in following Christ in this world. See Scot McKnight’s book, Kingdom Conspiracy: Returning to the Radical Mission of the Local Church. The point here is that in this diversity there does need to be a unity that in terrms of priorities, givens which should characterize every church in its own unique expression.
Differences again are not to divide us, but to help us toward unity paradoxically, as we see the gift from Christ that they bring.