Here is where I think some of the 'rub' is that Comfortably Numb may be trying to say (I don't pretend to speak for him - just trying to read between the lines -- so he can correct me as needed).
Christian compassion and giving is to be internally motivated out of a love of God and a love for our neighbor. It is not an external compulsion that motivates our giving and care. Knapp accurately and thoughtfully captured the essence of Christian giving and what is to be our heart. (Knapp - one day I hope you return to your faith roots - you have a good heart. But with that I affirm that one can have a good heart wtout a particular faith)
The rub is this:
Socialism is an external "mechanism' which exerts pressure via taxes forcing others to be "compassionate' in the way and to the recipients of the govt choosing. In that way, it is not different than any other govt - democratic or otherwise - it may exert more pressure than let's say a very conservative or libertarian democratic govt and it may exert less pressure than a full bore communist govt - looking at the extremes. Govts should be all about providing a safety net for its citizens - the debate is where to balance it out - how much 'giving' comes from private sector and how much from the public sector. If govts take so much through very high taxes it will leave little funds for individuals (Christian or non-Christian, religious or non-religious) to give freely as their conscience dictates to the individuals or organizations they wish to personally assist. I will say that the USA as the world's richest nation could have a greater and more encompassing safety net than what it does have. If our priorities were right we would be spending less money in some areas so that we could provide better health care and other assistance to the needy. However, the USA has also taken on the burden of caring for the world in so many other areas. Without our military, much of the world may be under dictatorships now. We are usually the first nation to help in a disaster - providing food, medical supplies, etc for people around the world. So we cannot flippantly say - just cut the military or cut foreign aid. We could however make better choices - like not fighting 2 wars in the MidEast at the same time. That could have funded a lot of safety net things here.
This isn't a matter of being compassionate or not - it is a matter of how or the method by which compassion is to be administered in a free society. Too much 'govt sponsored' compassion leaves less funds available for private donors (unless you are the very wealthy) to contribute freely as they desire.
So I think in an ideal world - socialism would work and we should and could all endorse it. But we aren't in an ideal world - there is too much selfishness at every level (sin) to make it not work. As a Christian we believe the ideal is yet to come. In the mean time we are called to render to Cesar that which is Cesar's and render to God that which belongs to God(our lives). And if we live in a society where Cesar is unusually large, we are to trust God for grace to give sacrificially both to Cesar and directly to our neighbor as our conscience dictates. If we live in a society where Cesar is small, then as Christians we aren't to let the god of materialism to take over our hearts and the best way to do that is to give generously and freely to those who are in need out of a hear of obedience to God and love for our neighbor.
Let me add: it isn't just in socialism that the sin of selfishness can ruin the utopia we try to build. Capitalism, at its core, has a lot of 'self interest'. So while the left leaning person may try to build a utopia through govt largeness, and while the right leaning may try to build a utopia via capitalism both utopias will ultimately fail because each are vulnerable to the seed of destruction - our internal selfishness or self interest.