Whether or not this is a good thing, it appears impossible for humanity to unify even in limited ways without dividing some parts of humanity off from others. And every attempt to unify human beings who exist on opposite sides of one dividing line find it necessary to create another line that is viewed as being more fundamental than the previous one in order to induce a cohesion that would not exist on its own. It is perhaps lamentable that even though we are all human beings the same, we simply cannot act towards others as if we are human beings but must have some sort of distinguishing between our sort of people, whom we can respect and be friendly to and enjoy, and those who are not our sort of people that we want as little to deal with as possible. We are used in our society to dealing with a world where blacks and other people of color simply do not feel safe in certain communities, and where many whites simply do not feel safe around blacks who are anything other than polite and nonconfrontational.
Yet it is by no means obvious how this is to be dealt with. On what grounds can blacks and whites be brought together? Most of my friends who are black are friends of mine because we share religious beliefs, even if our own experiences and backgrounds may be different. One can go to Ghana or Angola or the Caribbean or deal with those blacks that are in our own American congregations as fellow brethren with shared beliefs and practices and a language that comes from years spent listening to the same messages and reading the same scriptures with the same interpretations. Yet this form of unity presupposes a dividing line between believers and nonbelievers. When I was in high school I was friends with quite a few blacks and even more people of various other ethnic groups, but we were part of the same International Bacchalaureate program that also involved a dividing line between more ambitious students that wanted to better themselves through education and traditional students who were less driven. Those of us who were more ambitious fancied ourselves to be an intellectual elite that was superior to the common herd, and that tendency towards pride was certainly not an unmixed blessing.
No doubt one can think of other ways that the racial animosity or at least the separation of people can be overcome, but it can only be overcome by presenting common ground that units people who might be separated but separates them in common from other people. Some people may emphasize the importance of identity issues like race as a means of forming a political coalition that is divided in other ways. Still others may seek to build coalitions of class based on economic grievances or snobberies that will cut across identity concerns by presupposing that having the same standard of living can overcome other differences. We can be unified with other people on many grounds–the sort of music, art, and literature that we appreciate, our political positions, our race, class, gender, and other identities, being left-handed in a world of right-handed people, our religious beliefs, and so on. All of these means of uniting us with other people, though, separate us from others. If we unify with others on the basis of what foods we eat or do not eat, others will fall on opposite sides of the line from us. People who enjoy drinking do not tend to appreciate the company of sober and potentially critical people unless they are designated drivers who sacrifice their share of the fun in order to allow the others to party without risk arrest for DUI. The desire to be cool or part of an in-crowd requires the existence of those who are lame and uncool or outcasts. The unity of the fellowship of believers requires the existence of those who are disfellowshipped or unbelievers.
I do not know why this is so. I do not speak as someone who has cracked the code on how it is that we all came to be divided in the first place. Studies have been done to show that even extremely minor differences like hair color are sufficient, if they cause people to be treated differently, to lead to the sort of hostile group conflicts that result from racial or political squabbles. As we human beings have many identifying qualities, there are many ways that we can be divided from others. Anything that allows some people an advantage and others a disadvantage, regardless of the context or history involved, or even allows the appearance of advantage or disadvantage, is sufficient to pit people against each other. Our tendencies to resent any injustice committed against us and to view any undeserved advantage as being the result of merit or recompense for past injustices makes hostility between groups likely inevitable in any society that is marked by injustice and privilege, which is to say any human society that has ever existed and any that will exist from fallen and flawed human beings like ourselves. It is not enough, if we want peace from those on the other side of the dividing line, that we be just. We must also appear just to people who are not likely to give us the benefit of any doubt. How is that to be done?