Anarchist known for his political activism and writing. He was a leading member of the anarchist movement in the early 20th century. While living in France, Berkman continued his work in support of the anarchist movement, producing the classic exposition of anarchist principles, Now and After: The ABC of Communist Anarchism.
Sources:
1.) David Burns (2013). The Life and Death of the Radical Historical Jesus. Oxford University Press. p. 97. ISBN 9780199929504. "Alexander Berkman was a self-declared atheist attempting to lift the stultifying fog of the gods from the mind of humankind."
2.) "Impelling Forces". Sasha and Emma: The Anarchist Odyssey of Alexander Berkman and Emma Goldman. Harvard University Press. 2012. ISBN 9780674067677. "Berkman, an atheist, refused to be sworn in."