I used to participate in a Christian bulletin board that was populated mostly by fairly right wing folk who tended to be close to libertarian about the cold sins and very authoritarian regarding hot ones. They thought the government should not be involved in educating children or restricting business activities and certainly shouldn't be taking taxes from them but it was the governments business to restrict with whom or how you had sex. Sin was a big word for them but it only had to do with individual behavior, never corporate or systemic issues.
Whenever the discussion of entitlement programs came up, invariably someone would argue that the government should not be forcing them to help others... that indeed, were it not for the onerous tax system, they would take care of those in need. Now, these are folk who have more than a healthy respect for the fallen nature of humanity but they seem to forget their own theology when helping those in need comes up. Suddenly the better nature of human beings comes into play and we can count on good Christian people to do what is necessary to take care of those in need, providing food, shelter, education, etc.
Sin is not as important a word in my theological vocabulary as it is for them. Indeed, I rarely use the term. In this instance I would be more likely to use the terms selfishness, greed, and lack of a sense of community responsibility. I have no expectation that good Christian folk either could or would meet the needs of those in their communities if suddenly the government programs disappeared. For those of us who live in our comfortable suburban settings, it is all too easy to ignore the needs of those across the tracks. For those of us serving the needy, we know the needs are overwhelming. For those of us struggling to keep our heads above water, our children fed, the heat on... our needs are too immediate to have resources to help others.
Yes, I have seen and experienced the sacrificial love of many good Christian (and non-Christian) folk. As government funding for programs for the needy has shrunk, I have seen many good people work and give to pick up the slack. I do not believe that generosity is strong enough to overcome human greed or selfishness. I do not believe that enough good folk are open to the needs more than a few blocks away in a sustained way to meet those needs. I do not believe that without government intervention that there would be adequate resources to make a difference. The power of human sin is just too great. And I am always surprised that my brothers (they are all men) on that forum think otherwise.