Unity is not the same as uniformity. Unity, in fact, is the reconciliation of differences, and those differences must be maintained. We must actually distinguish things and separate them, usually at a cost to ourselves, before we can spiritually unite them (Ephesians...
The miracle of Pentecost wasn't that everyone spoke the same, but that all were "understood" in their native tongue. The fulfillment of Gospel is not assimilation/uniformity to one culture, but rather togetherness and mutuality within diverse cultural expression....
Diversity in the community of faith, when leveraged for the advancement of the kingdom, becomes an asset and not a liability. Unity in the Spirit does not require uniformity of perspective.