You happen to be Muslim like your parents. A boundary of religion is formed. All these boundaries are both inclusive and exclusive. They define a particular people group. And they exclude those people who are not part of the people group.
Every country is filled with people groups.
But closer examination will show a vast mosaic of differences. Take, for example, the city of greater Los Angeles. The numbers of Asians, Hispanics, and Blacks have been rising so fast that by the year 2000 there will not be an ethnic white majority. This will change the whole look of the city. Already there is not just one Asian community but Koreans, Chinese, Japanese, etc.