Marxism and socialism are two systems. What they have in common is the belief that assets and resources should be equally shared by all citizens irrespective of class or birth. Although it may appear that this was what Lenin was espousing, unlike Marx who insisted that revolutionary shared power must come from the work of the working class, Lenin believed the impetus - the plan, the intelligent thinking - must come from outside the working class.
Probably because he himself was from the more leisured educated professional class, despite his wish to make things equal, Lenin believed that the intelligentsia should lead the working class to manufacture change and equality.
The Soviet Communism is called a paradox of Marxism because the Communist society is contradictory to the Marxian theory. The fundamental component of the Marxian theory is it demonstration of the dependence of state and politics on the society. Marxism is a body of doctrine developed by Karl Marx and Friedrich Engels.
The Soviet Union was founded on a different ideology, it is argued that the expansion of the state in communist society is contradictory to Marxian theory, but the theory does have a genuinely paradoxical quality which lies in the tension between the political and its social basis in the socialist movement.