Brian McLaren calls it "motivation by exclusion". The basic idea is this: We brand you an outsider and make sure you know you are an outsider until you clean up your act...then we might let you in. We exclude others (presumably) in order to motivate them to become what we (and presumably God)want them to be. This being the case, we discuss different behaviors and infractions as abstract concepts, trying to be as objective as possible thereby making it easy to demonize anyone involved in said abstract behavior or activity.
Problem #1: It doesn't work.
Problem #2: One must completely ignore the Way of Jesus to adopt this way of being "a Christian". I have suggested on several occasions that it would be a life-changing study for many of us to simply go through the Gospels and observe who Jesus interacts with and how he interacts with them. The simply fact of the matter is that Jesus intentionally includes "sinners", outcasts, and the downtrodden. He makes a point of not condemning them. He never even mentions Hell to them (he saves that for the religious people, like me). He eats with them. He goes to their homes and socializes with them. He defends them. He builds authentic, unconditional relationships with them. Jesus doesn't deal objectively with abstract concepts. He can't. He has faces attached to all of it. He deals with it quite subjectively, and as "wrong-headed" as it may sound, this is exactly my point. I can't deal objectively with the concept of homosexuality because my uncle was a homosexual who contracted HIV and killed himself. He's buried in an outfit that belonged to me because he didn't have anything "nice enough" to be buried in. I can't deal objectively with the subject of alcoholism because I've known too many people who have struggled with it. On the other side of the coin, I can't deal objectively with the subject of pedophilia because I have a 3 year old daughter and have spent my adult life working with teenagers. It's not that the Bible doesn't say anything about homosexuality, drunkenness, etc. It says plenty. The point however, is this...if we have so put up barriers between "us" and "them" that we can discuss issues without faces attached to them...if we can discuss concepts in a way that demonizes entire people groups...then we are not walking in the Way of Jesus. When people become objects, we've lost our way and our voice. If we approach the subject like Jesus did (building authentic relationships, sharing our lives, intentionally including "others"), I suspect it will make things a lot more complicated. I also suspect that we will see more lives change than we have in generations and that the Kingdom of God will break through in powerful and exciting ways.