As a really good beginning to understanding that way Christian faith relates to the various other categories with which we find ourselves identifying and being identified, I would point to these words by Jonathan Wilson-Hartgrove:
[T]here is little evidence that most of American Christianity actually believes that the gospel offers us a new culture—a new ethnic identity in our sea of multiculturalism.
But if God really has made us part of a holy people, then we have been baptized into a new family whose way of living calls into question all the practices of our different cultures. This is not to say that black Christians have to become white or that Latinos need to act black, but rather that black, white, and Latino must become Christian. First Christian, then white. First Christian, then black. First Christian, then Latino. For Christianity is a culture—a set of beliefs and stories and practices that shapes our vision of the world around us and the decisions we make about ways to act in the world…. it is a culture that calls every human practice into question.
Obviously, this also means that we should be thinking of ourselves first as Christian, then as American. But as Wilson-Hartgrove points out, there is little evidence that most American Christians really think that way in their day-to-day life.
Again, I would call on all of us American Christians to ask ourselves who we normally mean when we say “we” and “us.” Do we mean we Americans or we, the church?