What arguments have been offered as to how Christianity is incompatible with a system of forced collectivism? Communism, as formulated by Karl Marx, incorporates several ideas including state mandated atheism, a removal of social classes, and a collective economic system.  Of these, the first is obviously incompatible with Christianity.  However, it is sometimes said that the second two are similar to Christianity.  This question focuses only on the last idea - a collective economic system where private property no longer exists in any meaningful way.

The first-century church, as described in Acts, does seem to embrace this idea in some ways.  For example, Acts 2:45:


  And they were selling their possessions and belongings and distributing the proceeds to all, as any had need. (ESV)


However, this was a voluntary act.  While voluntary collectivism is thus encouraged, this is perhaps different than forced collectivism, as practiced under communism.  Even in the story of Ananias and Sapphira (Acts 5:1-11) where the couple die not for failing to share their property, Peter implies that it would be morally acceptable to keep some property ("And after it was sold, was it not at your disposal?") - the couple died for their deception, not their lack of complete generosity. 

Among Christian theologians or denominations who view (forced) collectivism as incompatible with Christianity, what theological/moral arguments against it have been offered?
Here are some of the reasons I've heard:

In her book Seeking God, Esther de Waal summarizes an aspect of Benedictine (communal) life: the community fundamentally exists for the benefit of the individual, and not the other way around. Yes, the individual contributes to the community, and yes, the individual serves other members of the community, but if these did not serve the purpose of increasing an individual's holiness, there would be no point.

Christians, based on Genesis, consider all people to be made in God's image and thus worthy of certain things for their own sake. The idea of individual dignity seems to be absent from communism - instead the emphasis is on the workers as a group.

I heard a talk from (now Bishop) Robert Barron (can't find the mp3 online anymore unfortunately) where he discusses the Catholic Church's teaching on social justice. He discusses the works Rerum Novarum and Centisimus Annus and in particular he cites this passage from St John Paul:



Returning now to the initial question: can it perhaps be said that, after the failure of Communism, capitalism is the victorious social system, and that capitalism should be the goal of the countries now making efforts to rebuild their economy and society? Is this the model which ought to be proposed to the countries of the Third World which are searching for the path to true economic and civil progress?
The answer is obviously complex. If by &quot;capitalism&quot; is meant an economic system which recognizes the fundamental and positive role of business, the market, private property and the resulting responsibility for the means of production, as well as free human creativity in the economic sector, then the answer is certainly in the affirmative.


On a related note to the above, it is often pointed out that Christian communities, whether the ones depicted in Acts or later Monastic communities or any other since, while all is held in common, all is held in common with a local community. As an example, there is a sense that a piece of land belongs to a Benedictine monastery specifically and not &quot;Christians in general.&quot; (Note that this is one of the things that made the Franciscans shocking at the time - they actually didn't own any property, the Pope &quot;owned&quot; it for them.) In many implementations of communism, however, the state is free to re-allocate resources between groups or regions in order to increase overall utility.

There are probably others, but the above are a few common ones.