Had a phone conversation with my father, where we discussed the points where Christianity and socialism touch. A very important one is of course the centrality of alienation in both Marxism and the Biblical narrative - especially the Creation account. Where the alienation of the worker from the product of his work is precisely that which Marxian socialism seeks to overcome, the Creation account magnificently describes the alienation between man and his natural surroundings, no longer a luscious garden but a field to be laboured upon, controlled and fought against:
Cursed is the ground because of you;
in toil you shall eat of it all the days of your life;
thorns and thistles it shall bring forth to you;
and you shall eat the plants of the field.
In the sweat of your face you shall eat bread
till you return to the ground,
for out of it you were taken.
(Gen. 3: 18/19).
But the big question is of course what went wrong between the Communist Manifesto and the Gulags. Ultimately, there were tendencies towards historicism - the notion of historical necessity, and the subordination of individuals and groups of individuals to historical necessity - right there from the start, even though Marx may have been much more subtle concerning questions of historical determinism on the one hand and mankind as the master of his own history on the other.
But I guess these tendencies came to the fore much more starkly when Lenin attempted to lead a socialist revolution in a country with a very small working class. Bolshevism of course endorsed an ideology of the Party as the vanguard of the working class - the working class being by itself only capable of attaining a broadly reformist, trade-unionist consciousness. So essentially the working class became a project for the Party rather than a needed corrective influence upon the Party. After the revolution, of course, Stalin undertook industrialization, collectivization and the creation of the Soviet proletariat (and rural proletariat as well) at breakneck speed and at the cost of millions of lives - the original Russian proletariat having died in the Civil War, absorbed by the growing Party bureaucracy or returned to the fields. Man, humanity, and human life became a project of the future to which present generations were subordinated to and sacrificed to; rather than a present and concrete ultimate in our ideologies.
Back when I lived in the Netherlands, I used to devour the texts of the East German playwright Heiner Mueller - the chronicler of the GDR, who started as a loyal socialist but became increasingly sceptical towards the end of his life without ever totally abandoning his ideals. One of Heiner Mueller's plays, Mauser, magnificently presents the question of "What is a human being?" The play itself reads like a comment/excerpt of Brecht's Die Massnahme. In Brecht's play, a group of agitators on a secret mission in Northern China decide that they should execute one of their own for the good of the collective. Mueller's Mauser is a dialogue between the Party, the firing platoon, and its victim, set perhaps during the Russian civil war. There is a certain merciless rhythm in the text - that of concrete stakes being rammed into the ground by cold and not at all benevolent machinery, and at the same time biblical turns of phrase (In Vitebsk as in other cities) are not hard to find.
Unfortunately, I haven't got the text right here, but I found an excerpt which I tried to translate below. There's no way this does justice to the text, but it might give you an idea:
Your assignment is not to kill men, but
enemies. For man is unknown.
We know, that killing is labour
but man is more than his labour.
Not until the revolution is finally victorious
in Vitebsk as in other cities
will we know what a man is.
For he is our labour, the unknown
behind the mask, the one buried in crap
his history, the real one behind the growths
the one living in the fossizilations,
because the revolution will tear down his mask,
will erase the growths, will cleanse the dried crap
from his history, from his image. The man, with
claw and tooth, bayonet and machine-gun,
rising from the chain of generations,
tearing his bloody umbilical cord
in the flash of the real beginning knowing himself
and others, each according to their difference.
Excavate, root and all, man out of man,
what matters is the example. Death means nothing.