In all honesty, I can't quite understand a perspective in which Original Sin can be personal. It is quite literally not the person who has sinned, it was their ancestor (Adam). An individual could live a perfect life and still be condemned. However, what is often associated with Original Sin is the idea of that people have an inherent tendency to sin. That is, it isn't just Adam's sin that condemns people, but rather the various sins that they have committed during their life. However, while this does here have a religious flavor, it fits in with a general discussion that exceeds the bounds of religion: are people basically good or basically bad? It is true that most Christians do believe in a human sinful nature, and this belief can be a personal judgment, but Christians can still fall on either side of the above philosophical question. For example, I tend to be on the "basically good" side of the debate. This is revealed in such statements of mine like this:
Most humans want to be good: evil usually happens because people have justified it to themselves, if only in the moment of actually committing the act.
In short, when a religious person does say that a friend has a sinful nature, it isn't a fully religious stance and it can be barely personal (just to the extent of saying that the friend is human and that all humans are imperfect: I would generally contend that entering into a relationship realizing that people aren't perfect is desirable and healthy).
Of course, there are very mean, very horrible Christians (I would generally like to say that they aren't Christians at all, but that gets into another who set of difficulties). They see people as nasty to those who are not their friends, and often nasty to those who are as well (a trait that these Christians, unfortunately, often share). They see people are barely restrained savages who'd as soon eat your face as look at it. They do indeed fall on the side of "people are basically bad" and see religion as a necessary restraint to keep that horribleness in check. My point being, however, is that this isn't caused by the concept of Original Sin, nor is it caused by a general perspective that humans have a sinful nature. It is a perspective that goes beyond religion, and it is one that atheists can share as well (with, admittedly, different justifications).
Just to be clear on a somewhat associated point: Syna, in my previous post I was specifically presenting a perspective that was biased towards being "somewhat nice" towards Christians, with the intent of showing that it is quite possible to believe in certain perspective and for those perspective to not be problematic. I did not mean to indicate that there aren't jerks who are Christians: such a claim would be laughed out of the forums, since we all know far better than that.
