Whether or not one believes liberation theology to be influenced by Marxism, it is not difficult to recognize certain parallels between the two, in both the conception of human problems and the means advocated for overcoming the problems. In each case [liberation theology and Marxism], the problems of society, whether termed evils or sins, are seen as resulting from inequitable distribution of power and wealth, and the solution lies in removing these inequities and the attending oppression.
The assumption of liberation theology, as of Marxism, is that it is the economic struggle, and particularly the inequities in power and property, which determine human behavior. Presumably, those who are promoting such inequities are great sinners, while those who fight injustices are not. In fact, certain liberation theologians will in some cases regard a particulate action (e.g. killing) as sin if it is committed by and oppressor, but not if it is committed by the oppressed in the struggle to remove inequities. The removal of inequities is believed to result in the removal of the occasion of sin as well.
In reality, however, this theory seems not to have worked out quite this way. In the former Soviet Union, where the classless society was achieved, there were still notable power struggles among the leaders and repression, even involving the use of violence, of those outside the power structure, as millions of Hungarians, Czechoslovakians, and Poles could testify. It appears that possession of adequate resources for the supplying of the basic necessities of life does not negate the tendency to seek one’s own satisfaction, even at the expense of others. Redistribution of power and wealth does not eliminate “sin”.
Millard Erickson, Christian Theology, p 610