I don't think Christian privilege is a difficult concept for most atheists living in predominately Christian countries to grasp. Most of us have had more than enough experience with it to know what it is like. That does not mean that it is an easy thing to explain to others, especially Christians who are often oblivious to it. How might an atheist describe what Christian privilege feels like to those who don't get it? There are many examples from which one could choose, but one that stands out to me and seems particularly appropriate this time of year takes place in many households during Thanksgiving.
To set the stage, we need to imagine a Christian family that enjoys Thanksgiving and likes the idea of sharing it with strangers by inviting them to dinner. To be clear, there's nothing wrong with this. In fact, we might consider it a gesture of goodwill. Perhaps the son's friend from college is an international exchange student and it is either not feasible for him to return home to visit family or would not make any sense that he would do so because people in his country of origin do not celebrate Thanksgiving. Everybody else is clearing out for Thanksgiving, and it looks like he'll be left behind. Invite him to dinner!
A variety of problems could emerge even before the family sits down to dinner (e.g., why does nobody bother to see whether he's familiar with what they are serving?), but we are not going to concern ourselves with that sort of thing here. We will focus instead on the particular problem that tends to emerge when the family sits down to their Thanksgiving dinner: the mindlessly insensitive sectarian prayer.
The family clasps hands, bows heads, and launches into the sort of Jesus drivel they like to bring out on such occasions. Because it is Thanksgiving and because they are used to doing this on Thanksgiving, they put everybody at the table on the spot and ask them to share what they are thankful for as part of this prayer. Of course, nobody has prepared our guest for any of this. In fact, nobody has given any thought to what it might be like for someone from another country who might even not be Christian (gasp) to be subjected to this ritual.
What do you suppose most evangelical fundamentalist Christians would say if you were to ask them how comfortable they would be if the roles were reversed and they suddenly found themselves participating in Muslim or Hindu prayers? I think you could predict what most would say with an impressive degree of accuracy. And yet, they rarely bother to consider that their guest might feel similarly. This, my friends, is Christian privilege.
Have you ever been in a similar situation where the people at the table carried on like this despite knowing that you were an atheist? I certainly have. What are we to make of this? Of course, they can behave like this. This isn't a question of their rights. The question is whether they should behave like this when they've invited someone to dinner who they know doesn't share their beliefs. The answer seems clear.
So if you have been in these situations, what do they feel like? The first word that comes to mind for me is alienating. It is kind of like they are going out of their way to highlight that I am the "other." I'm not part of whatever they have going on, and it is important for everyone there to know that. But mostly, it is important for me to experience that sense of separation and otherness. I am not claiming this is their intent; I am just trying to describe how it feels. Some will say I should just be grateful I was invited at all, but I disagree. Given the choice, I'd rather steer clear of people who behave like this.