Marxism is defined by Wikipedia as the philosophical, social theory and political practice based on the works of Karl Marx, a known proponent of a social revolution to achieve full transformation of the state from capitalism to socialism. Its aim is to achieve equal distribution of wealth to all members of the society. This is totally opposite to the theory of capitalism that is often the system observed in western countries. Here, the labor force is treated as the major factor in the production of wealth rather than capital which is held only by a few.
Existentialism on the other hand is a philosophical movement that gives meaning to human's existence in this world and seeks to value one's existence. Here, the meaning of life is given paramount consideration over other aspects such as politics, economy and sciences. It is opposed to the western's ideology on rationalism. Its core idea is that reality is not the consciousness but "being in this world."
The first three principles are somehow related to each other in the sense that nationalism is the moving force behind the pursuit to industrialization and Marxism. Thus, it is nationalism that justifies the continued attempts to fully industrialize the economy and to distribute the wealth of the nation.