Not only were Marx and Engles Atheist, they were rabidly so. When Lenin took control, his attachment to Marx and Lenin was supplemented by his attachment to Nietzsche. Under Bolshevism, the Russian population was to be de-kulaked and de-religioned. And an organization arose to help out with that: the League of Militant Atheists. Under the Atheist Bolsheviks and the LMA, it has been estimated that tens of thousands of priests, bishops, and religious administrators were murdered. 13,000 priests were "dekulakized in 1930" alone. Tens of millions of adherents were murdered as well. Further evidence of Atheist foundations of the purge is this anecdote: all church bells were seized by decree, because "the sound of bells disturbs the right to peace of the 'vast majority' of atheists in the towns and in the countryside".(1)
Although bloody and serious, the purge was not complete. In 1936, 28% of Orthodox churches still remained "in service". But by 1940, the 30,000 churches prior to Lenin had fallen to 500 (2).
"The Soviets' official religious stance was one of "religious freedom or tolerance", though the state established atheism as the only scientific truth. [83][84][85] Criticism of atheism was strictly forbidden and sometimes resulted in imprisonment.[86]In actuality we'll never know how many were murdered by Atheists for Atheism. But the number is obviously huge.
The Soviet Union was the first state to have as an ideological objective the elimination of religion. Toward that end, the Communist regime confiscated church property, ridiculed religion, harassed believers, and propagated atheism in the schools. Actions toward particular religions, however, were determined by State interests, and most organized religions were never outlawed. It is estimated that some 20 million Christians (17 million Orthodox and 3 million Roman Catholic) died or where interned in gulags.[87] Some actions against Orthodox priests and believers along with execution included torture being sent to prison camps, labour camps or mental hospitals.[88][89] The result of this militant atheism was to transform the Church into a persecuted and martyred Church. In the first five years after the Bolshevik revolution, 28 bishops and 1,200 priests were executed.[90] "(3)
Any claim that Atheism was not a part of the Communist massacres is delusional or dishonest or both. Historical revisionism must not be allowed, ever.
Note 1: Black Book of Communism, p 172.
Note 2: http://www.realclearreligion.org/articles/2012/08/20/the_new_soviet_league_of_militant_godless.html
Note 3: http://religion.wikia.com/wiki/History_of_the_Eastern_Orthodox_Church