There can be little doubt that Nietzsche is the most important figure in modern atheism, but you would never know it from reading the current crop of unbelievers, who rarely cite his arguments or even mention him. Today’s atheists cultivate a broad ignorance of the history of the ideas they fervently preach, and there are many reasons why they might prefer that the 19th-century German thinker be consigned to the memory hole. With few exceptions, contemporary atheists are earnest and militant liberals. Awkwardly, Nietzsche pointed out that liberal values derive from Jewish and Christian monotheism, and rejected these values for that very reason. There is no basis – whether in logic or history – for the prevailing notion that atheism and liberalism go together. Illustrating this fact, Nietzsche can only be an embarrassment for atheists today. Worse, they can’t help dimly suspecting they embody precisely the kind of pious freethinker that Nietzsche despised and mocked: loud in their mawkish reverence for humanity, and stridently censorious of any criticism of liberal hopes …
Reared on a Christian hope of redemption (he was, after all, the son of a Lutheran minister), Nietzsche was unable, finally, to accept a tragic sense of life of the kind he tried to retrieve in his early work. Yet his critique of liberal rationalism remains as forceful as ever. As he argued with masterful irony, the belief that the world can be made fully intelligible is an article of faith: a metaphysical wager, rather than a premise of rational inquiry. It is a thought our pious unbelievers are unwilling to allow. The pivotal modern critic of religion, Friedrich Nietzsche will continue to be the ghost at the atheist feast.
–John Gray in the New Statesman